Profit and TAS


Yes, I'm selling a HP 15c on eBay under my nick name Datamath-Calculator-Museum.

No, it is NOT for the profit.

Please let me share some facts with you:

The Datamath Calculator Museum is not for profit, it is a hobby. But it is not a cheap hobby, every collector knows that the last 10 items you are looking for are pretty expensive.

I decided long time ago to avoid any Google Ads or similar advertisements on my website and to make all scanned and PDF'd manuals available for free download.

I'm on eBay since 1999 and changed my ID in 2007 to built up a good reputation in selling calculators to COLLECTORS (not bargain hunters). In the past 12 years of buying calculators on eBay, I received a lot of crap. I could easily sell dozens of boxes of 25 trash calculators, each.

Each USED calculator I sell is tested and cleaned twice: The day I receive it and when I take the pictures for the auction. I describe every flaw I notice and take crisp pictures of each calculator. I accept returns and the rate is far less than 1%. The last one was an ADLER with a non-working [4] key. No idea how I could miss this...

I received from other "Pro" calculator sellers multiple requests in the past two years:

1) Sell only for a (high) BUY-IT-NOW price
2) Let's agree on minimum prices for some "rare" calculators

I still sell my calculators auction style - but changed recently the minimum price from $9 to $19. I had a lot of calculators ending up at $9.50 or so averaging my "profit" (w/o eBay fees!) around an hourly rate LESS than MINIMUM WAGE in Upstate NY!

I received a lot of emails from buyers, too:

3) Can you make a BUY-IT-NOW for this calculator?

Answer is always the same: NO - and a few names are already blocked from my auctions for this reason.

And the HP 15c you might ask now?

Four of my international collector friends asked me for some assistance in purchasing HP 12c and 15c's and SHIP them.
I simply purchased two each, more - expecting some change for my next great purchase of either the Exactra 100 prototype (asking price is two grands!!!) or a TI-88 in the transparent housing (no asking price so far).

Thanks for your time reading through this message.

Best regards,


Great post!

I really don't understand the TAS bashing going on in this forum, especially regarding sellers. I too have considered reselling some of my extra HP15CLE's for some profit, but just haven't. Would that make me a bad guy?

IMHO, Joerg's success with unique inventory, great photos, accurate descriptions, and stellar track record INCREASES his final prices as the best calculator seller on TAS.

Although I have never bought anything from Joerg, I would not think twice about doing so.


Edited: 26 Sept 2011, 1:31 p.m.


Thanks - makes you a good guy!!!

Multiple calculator collectors asked me to sell THEIR calculators under MY name.

I never did. Makes me a good guy? Probably not, but a stupid one'

Real life: I am an engineer, not in sales...


BTW: Top bidders on the two 12c and 15c auction are from France, Israel and Brazil. All but one are returning customers!


I'd like to add my voice to Geoffrey's (and everybody else's), and come to the defence of Joerg. I have bought a few things from Joerg over the years, and I have always received excellent service, above and beyond. Before I did, and outside of TAS, Joerg has always been helpful, and has a good sense of humour. Because he is well-known, and trusted, his calculators would indeed go for higher prices, but that's worth paying for (I wish that when I trim my collection I get as good prices as he does).

As for the re-selling of his surplus HP-15C LE (and HP-12C 30A), I bet he was as surprised as I was to see them go at such a premium!

Why so much? I don't know for sure, but I would hazard that quite a few people are not aware of Samson Cables or the very few other people who would currently ship these calculators outside of the USA, and go to TAS simply because that's the best place they would know.

Carry on Joerg! (oh, and can I have a discount next time ;-))



Joerg you're my Hero !!!! :-)
But though we could have bought 123652 15LE :-)))
Let's stop being an engineer to be 15LE seller :-))))
You're a great friend we should respect and thanks to you
Hugs from Singapore

I don't like the idea of buyers being victimized by people like Coburlin, but you don't do that!. As long as the item is fairly described, then how could I possibly object to an open auction? I think I even stand on dubious ground when I criticize Coburlin, though I just can't get a bad taste out of my mouth with him. I think the problem is that he's obviously not an aficionado and he's taking advantage of people who might be aficionados. Just as obviously, it's clear that you are an aficionado. You fairly describe and document what you sell. If your auctions go higher than what I would pay, it's none of my business.

And good for you for not agreeing to collusion on prices. We who haven't filled the last 50 slots in out collections appreciate it. :)

Best of luck,


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