Ebay bids on HP41CX, twice.


The first one I bid on I stopped at $110 and it went for 140 bucks, the second one I went higher to $200 and someone out bid that and I guess it will go for $202.50 unless someone else chimes in. Do you think these are scams? I Think the seller has a buddy whose job it is to up the bid to somewhere the seller wants, of course if so, like in my case, it failed because I refuse to go over 200 bucks. What is the 'bluebook' on the 42CX? Is there an actual bluebook? I saw posts here that said you could get one for a bill and a half but that does not seem to be the case on Ebay. So what is the bluebook for a 41CX and do you think I am right about an ebay seller's buddy?


Is there an actual bluebook?

Yes. It is called "completed listings" on EBay. The real "bluebook" is what others are willing to pay.



Yes. It is called "completed listings" on EBay. The real "bluebook" is what others are willing to pay.

How do I use 'completed listings'? I saw the window with it but was unable to connect it with anything, like an actual product.
So do you think ebay sellers use buddies to force up bids?


Don, if you click completed listings, it will prompt for your ID and password and then show you listings that have recently closed for the item you searched for, so you can see what real buyers paid for those items. At least that's how it works for me.

I suppose some sellers use buddies to jack up the price, but the seller would have to pay the completed item fee to EBay in those cases, and I gather those fees are not cheap (I'm only a buyer, not a seller).


Again this is quite confusing..


One recent quirk of completed items on ebay.... You have to uncheck "Include title and description", refresh your search, and then the "completed listings" option is available for selection.



OK, thanks - I have to print that...no---I rather sell through the museum to real HP-nuts (full/½) instead of e-bay sharks (I know that dolphins dwell there, 2)


Simple algorithms (with substantial readily available inputs) could detect shill bidding by correlation of bidder-seller - its not rocket science - and I doubt if implemented somebody could get away with this for any duration of time.

Whether eBay enforce their shill bidding policies are another matter.

Edited: 16 Nov 2008, 11:34 a.m.


Simple algorithms (with substantial readily available inputs) could detect shill bidding by correlation of bidder-seller - its not rocket science - and I doubt if implemented somebody could get away with this for any duration of time.

Whether eBay enforce their shill bidding policies are another matter.

So like my chess playing site, redhotpawn, they detect chess program users by correlating how similar a move it to a given program CPU combo. So the shiller could not do it more than a couple of times without getting caught. Any way to tell how diligent Ebay is on this issue?


In my ebay experiences, I have suspected that shill bidding occurs occasionally, but not very often. Those times I suspected it, after a few months follow up, I saw accounts deleted by eBay. They have the information necessary to keep shill bidding at bay, and it appears that they do a fairly good job. I agree with a previous poster, someone may get away with it a couple of times, but it is unlikely they can do it consistently.

Another thing that leads me to believe this does not happen very often are my own selling experiences on ebay. My stuff tends to go near (or quite often higher than) recent completed auctions for similar items. This would not happen if shill bidding were common.

If you are not very experienced with HP-41CX auction sales (I've watched them for over 10 years) then the final prices may seem highly random. But, there are many clues in every listing about the real value of a particular HP-41CX. I just looked now, and there is one listed as 'pristine', when the photos (which seemed to be staged to prevent conveying much info) hint at at least a couple of things that are not pristine about it. It likely will not sell for a high amount (if it sells at all), because most experienced HP-41 buyers on ebay will consider it a high risk purchase. Other CX's offered for sale, without any observable warning signals, and from reputable sellers, will typically command $200 to $300, depending on minor details and included accessories.

If you (or anyone else) would like help analyzing active ebay ads for HP-41's let me know, and I'll tell you what I'd watch out for on a particular item.

Full disclosure: My ebay ID is kctongo, and I currently have no items for sale on ebay. (They, and their cohorts PayPal, kind of have me pissed off right now, another story).



I agree with the issue at hand; there seems to be a significant issue with 'price handling' on ebay. However I would like to chime in on ebay’s behalf (not something I ever thought I might do) regarding a very shady bidding history on my current auction.

The situation is: I currently have an auction where there appears to be a bit of shifty bidding. First, one member placed a rather significant bid on my auction. The sale price moved up to, apparently, the next bid higher than the current bidder's maximum (i.e., the bid went to $192.50). I was happy with the spike...then within a few hours the bid was retracted as an 'Administrative Cancellation' and the bidder was reported to me as "Not a registered user". This bidder (silveriob2005) is now not even listed on the bidding history. Obviously the active bid went back down to the prior $130). Now for the meat of this diatribe: a short while later, 'another' member (physicsnerd.12) bid once only and just below the value the prior bidder exceeded. It simply looks like a probe for the bid limit and another bid to raise the bid up to that value. If this happened to an auction I was looking at, I would quickly leave that one alone, remember the seller, and never ever consider them for a future purchase.

I received a very prompt email from ebay and then we discussed the issue over the phone. So, in light of that, I would say that ebay is at least making an effort in the shill bidding department.

I really have no idea what this member would have to benefit from this. It certainly doesn’t seem like they are really interested in winning my sale. I have my suspicions, but they edge on conspiracy. Off and on, you see, I have been selling my collection and, while checking the market, I, as many of us, noticed there are a couple of sellers that purchase cheap and sell only in a 'buy it now' format for outrageous amounts. This generally benefits me and I am certainly guilty of hoping my sale will be higher because of these folks are consolidating the market. But, are these cats working the market and trying to throwing suspicion on other sellers? Or are they using methods like this to artificially jack up the ‘bluebook’ price so their ‘buy it now’s have a better shot at selling?

I don’t know. It is certainly sneaky, if true. And it bugs the tar out of me. Perhaps the classified section is going to be my venue.

*Stepping off my soap box*
Thanks for the thread where I could vent my frustrations.


If you would like to take gander at the bidding history on the auction I am referring to, look for the pair of 41c units that are finishing this afternoon. My ebay ID is 'landon.rosspe'. The bid from silveriob2005 occurred at: (taken from the cancellation section of the page since it doesn't show on your version of the bid history).

Bid: Nov-12-08 16:59:48 PST
Cancelled: Nov-13-08 13:16:06 PST

The result was that physicsnerd (the only bidder for $185) moved the bid up to $190 without actually placing a real bid.
Your thoughts? Or am I just a crazy old coot?



2 diffi-cult

Your thoughts?


My mind has way too little going on of late.


Hi Dallas!

I did not check the forum until just now. I see your item ended yesterday.

As I see it, the cancelled bid was from a buyer who had a feedback rating of 44. I'm only guessing, but your situation looks similar to one that I had early this year, although for me, ebay did not catch it until the auction ended. Someone had their ebay account hijacked (probably used a weak password) by someone in Africa. The hijacker placed a winning bid with the hijacked account, and when the auction ended, sent me a bogus email that was supposed to look like it was from PayPal, saying that payment had been made, and that I was to immediately ship the item to Africa. And there was the part about how the buyer's payment would not show up in my PayPal account until I had actually confirmed shipment. Obviously I am not that dumb (contrary to published reports). Before I had actually got to the email, Ebay somehow figured out the users account had been hijacked, sent me an email telling me that they had to cancel my auction (after it ended), and gave me an automatic refund of my listing fee. Of course, I had to recreate the listing, since it had totally be removed from ebay, but all eventually ended well.

I'm guessing that is what happened to your auction, primarily because the bidders feedback rating was not real low.

I'd also wager that the other bid you got was just a random occurence, not related to the cancelled bid. Your items seem to be definitely worth at least the amount of the second suspicious bid, so it would not be unusual to see a bid of that value. The package appeared to go for a fair value.

Are you a crazy old hoot? That I don't know. :-) But it appears the only thing weird about your auction was the one cancelled bid, probably from a hijacked ebay account.

Dan Grelinger


I would have to agree with you after a bit of thinking (and my wife's cold/efficient evaluation of the situation).

It was most likely more of a coincidence than anything else. But I am still pleased at the speed with which eBay contacted me.

I, too, am quite pleased with the final sale. I put a fair bit of time in replacing the LCD & buzzer on the 41c and repairing the card reader. Although the card reader was very straight forward, the LCD is quite a time-sink. But still not bad if you are savvy with a solder iron. This was, by far, easier than rebuilding Pioneer keyboards; I thought I would go crazy while testing different ways to keep the 'sandwich' mashed down while my epoxy cured. I settled on the balsa wood grid with a brick on top in the oven at 45degreeC for two days. But that is truly a different conversation: "How to Rebuild a Pioneer Keyboard from Salvaged Parts", I hope to get a chance to write it up and provide good photography to boot. I just need to find, say, a 42s with stuck key domes and a 17bii with a functioning keyboard. Too many projects on my bench...

I do have a few last members of my collection to send out into the world and I should have enough funds to finish the rather nice transformerless output tube amplifier I have been working on over the past year. Collecting parts is so tedious; too many 'audiophile' vampires out there. (So, eclectic coot may be fair, eh?)

(And this is getting far too off thread, as folks here say.)

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