Analysis of Coburlin


I have generally reframed from replying to any of the comments that have been made concerning Coburlin and his E-bay practices. But I have been wondering about his success ratio. So I decided to do a totally unscientific analysis using the past deals as reflected in his existing Feedback.

I found the results very interesting.

The period covers Feedback from Sept 29 thru Nov 25. During this period, he bought 50 items for $1925 plus shipping. He also sold 13 items for $2900. Not a bad profit you might say. He still has 37 more items to sell at a highly marked up price.

What is the most interesting is the following:

Of the items bought, 17 were true Buy It Now, 9 were sold early BIN, and 24 were full period bids of 5 to 10 days in length.

The True Buy It Now included:

Three Hp-200LX for $50 each.

HP-41CV W/Survey Module for $60.

HP-41CX for $100

HP-15C for $60.

Each of these Items were available for a short time for ANY ONE OF US to purchase at these prices. He just did it before we did. That's the way it works.

The items that went for the full period included the following:

HP-15C for $61.25 (10 Days)

HP-35 for $13.83 (7 Days)

HP-41CV for $95 (5 Days)

HP-41C X-Func Module for $4.99 (7 Days)

HP-15C for $100.88 (7 Days)

HP-35 for $52 (5 Days)

HP-15C for $86 (7 Days)

Again, ANY ONE OF US could have also bid on any of these items and probally bought them for a faily resonable price.

I realize there are many here that do not like the fact that he will attempt (and the key word is attempt) to re-sell these items at a very high mark-up. And the fact that he is also quicker to purchase low BIN offers, but any BIN is available for any of us also.

I have to admit that I have bought items extremely cheap at yard sales, flea markets and then re-sold them or traded them at the higher going rate. I'd be willing to bet that most of us here have done that also. But isn't that how most of us fund our hobby? I have picked up items cheaply at flea markets, etc, that I really didn't want just for the purpose of trading or selling it for something I really want. I think most hobbies work this way. I guess the phase "going rate" might make a difference, but I did re-sell or trade at a profit. Of course there are those many items I have bought over the years that I ended up giving away because I was the only person who thought it was a bargain at the time I bought them.

The main difference is that Coburlin does all his buying and selling in a very public way and the mark-ups seem extremely high to most of us and that irritates us.

I guess my main reason for writting this is to try to put some perspective on it. Any one of us could have also bought a fairly cheap HP-15C, 41CV, 41CX or 200LX if we had been quicker. I'm sure that many of us HAVE bought items using BIN that has also irritated Coburin when we were quicker than he was.

Several years ago, I was at a Ham Radio Ham Fest (Flea Market) and the table I was at had several TI calculators on it for sale. I wasn't interested in the TI's, but the person behind me was astute enough to ask the dealer if he had any other calculators for sale that he hadn't put out on the table. Turned out the dealer had 15 HP-41CV's with cases, modules, and other accessories. The person who had asked, ended up buying the lot for $5 each ($75 total) while I could only look on in envy. I learned a valuable lesson that day.

Time to Quit Rambling. I'm not trying to stir anyone up, so please no flames.



A very poor analysis, because it misses the whole point of what ticks people off about this Coburlin. No one here has ever said Coburlin can't buy and sell to make a profit. What has been said is Coburlin's attitude towards his own customers is atrocious. He feels they're a bunch of dumb nerds who deserve to be taken. He even said at one point his customers were stupid. Ready to buy?


How many aucions where bought back by Cobubba (through other accounts) so he could drive the price of calculators up????

Edited: 26 Nov 2005, 2:22 p.m.


Just re-read my post and realize the last sentence might be mis-understood:

"Time to Quit Rambling. I'm not trying to stir anyone up, so please no flames."

The phase "Time to Quit Rambling" was made to myself, not to anyone else. I felt I had started to ramble in my post so I wrote a direction to myself. I should Ihave type "Time for me to stop rambling".



Bill, excellent analysis. You are right, any of us could do what he does. He may be obnoxious, so what. If I see a calc I really want on Ebay, I know that serious bidders will raise the price and he will dropout. I'll bid up to my max, and that's it. Coburlin is no different than lots of professional Ebayers who have software that scans for new items and gobbles up low BINs. Que sera sera.



Great analysis! Thank you very much. This shows a bit about the "market" for used calculators.

The period covers Feedback from Sept 29 thru Nov 25. During this period, he bought 50 items for $1925 plus shipping. He also sold 13 items for $2900. Not a bad profit you might say. He still has 37 more items to sell at a highly marked up price.

I think this is a very low profit for the time spent.

Assuming that shipping would take away another USD 300 - 600, net profit is around USD 400 to 700. And this is defintely low for two months. Also, storage is not yet taken into account.

Let's assume that each buy and sell takes about 1 hour. This would result in a "salary" of USD 6 - 12 per hour. Not exactly thrilling. Varying the assumptions might result in an hourly rate of up to USD 30, which still is low for self-employment.

In addition, there is always the risk associated with collector's markets. Items may go out of fashion, and you may end up with a lot of "dead capital".

What we can learn here is that buying and selling old calculators, even HPs, is not really profitable. From an economic point, there are definitely better opportunities (well, this probably depends on your level of expectation.)

In my opinion, old calculators are a matter of the heart, not an economically sound and profitable business.

Best regards



I would like to know if he uses special software to keep the track of the auctions, because, if not, he would spend many hours in front of a computer to track the auctions, make offers of BIN,..


BIN stands for...?


BIN = Buy It Now


It see he spends much time on the PC, since he does the first bidding on many items and contacts the sellers askng them for an informal BIN value so hecan end the auction early. Cobubba is cheap! I recently outbid him on an HP71B with 32K RAM and three manuals. It was an easy win, because he was tooooo cheap in his bidding.

Edited: 27 Nov 2005, 7:19 a.m.


a little bit of Illuminatti:

have you ever thought he might be a cop or something and is washing some "dark profits" in this way?

or may be a smugler of any kind and infortunatly choose our dear hobby to make his covert operations.

by what you told, he was able to clean up or "pass" a good amount in a fairly short time.

if he declares it, would it be good money? yes.

so, may be he never bought anything or sold anything. it´s all fake.

is it absurd?

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