WAS: HP vs. TI on eBay auctions


Hi Michael, Maximilian et.al,

I guess the keyword "RPN" in the auction header was the trigger word. I just placed anouther bunch of calculators on TAS an played for the statistics with the auction header:

1) RPN CALCULATOR WEEK #9: Novus Mathematician aka 4515

2) CALCULATOR HISTORY: National Semiconductor 4650 - US

Both calculators are listed in the Vintage Calculators category and should get a similiar number of hits.

As additional proof of the "RPN" idea I use a third calculator:

3) ONE TIME WONDER: Ultra rare IJI MINI calculator - 1972

This one should draw MORE ATTENTION than all others ;-))

My HIT counters are public and I will report you the "WATCHED #" from eBay.

Have a great weekend and enjoy calculator hunting.




By posting this before the auctions are over, you've biased the results.

- Pauli


This would imply that most of the eBay bidders read this forum frequently.

Time for another poll:

How often do you (# per week)

(1) Read this HP FORUM?

(2) Search eBay.com for (RPN) calculators?

First entry:

Joerg Woerner:

(1) 2..3 times per week

(2) 3..4 times per week



1/ lots
2/ never

But I did look at some of your auctions after you mentioned them.

- Pauli


  1. Daily unless on vacation (no net access) or swamped with work.
  2. I have eBay search for me, I then read the emails I get from eBay about once or twice a week. Next, I put into Auction Sniper anything that I'd be interested in and then forget about it. I usually lose (too cheap), but win about once every 3 months.


For me:

1. Every day.

2. Never. I only really search for "HP Calculator", or "Hewlett Calculator". I still suspect that it is HP, not just RPN that is the key (and the majority of HP's are RPN).



1 = Daily, or thereabouts
2 = Weekly, or thereabouts


Read this HP FORUM?

3# per week:

- more when topics are on calculator repairs,

- less when topics focus on the next Hp calculator release,

- near epsilon when discussion is on how many $$$$ were spent on auction xxx :-)

Search eBay.com for (RPN) calculators?

Permanently on Hp-80*, Hp-81 & Hp-970* (Okay, latter is not really a calculator...just the display)


Edited: 24 Apr 2010, 10:13 p.m.


(1) Twice a week, mostly on weekends lately.

(2) Never.


1) every day

2) hardly ever


1) every day, several times per day
2) every day


sorry guys, I had misread the questions :

1) every day, several times per day

2) rarely, preferred search is "HP Calculator" or "Hewlett Packard Calculator", strange but true, the two queries return different items (sometimes).

have a good weekend Alberto


1) Read the forum: Every day, at least once.

2) I have an automatic search on TAS for HP calculators. 80% of calculators in my collection were purchased on auctions!

Joel Setton



1.) HP-Forum: Daily (apart from the days that my job keeps me away from the internet)

2.) eBay.com: Rarely (intercontinental shipping fees often exceed the amount that I'm willing to pay for the calculator alone), however eBay.de almost daily. I'm not looking specifically for RPN calculators, but for calculators with luminous displays.

Regards, Max


Hi Joerg,

I hope TI does not limit your privileges with them when they see you involved with HP calculators!




For sure not ;-))



1) +/- daily
2) +/- daily
3) now i'll have to add Datamath's ebay page


Here wer are:

1) RPN CALCULATOR WEEK #9: Novus Mathematician aka 4515

116 hits, 14 watchers

2) CALCULATOR HISTORY: National Semiconductor 4650 - US

92 hits, 11 watchers

Both calculators are listed in the Vintage Calculators category and should get a similiar number of hits.

As additional proof of the "RPN" idea I use a third calculator:

3) ONE TIME WONDER: Ultra rare IJI MINI calculator - 1972

128 hits, 16 watchers

Conclusion: "RPN buys not too much on eBay..."

What do you think?



Hallo Jörg,

don't get me wrong but the ads section is somewhere else, isn't it?


Joerg; I looked at a couple of your finished auctions for non-hp RPN calcs. There's no way i can know how many total watchers there were at the end but i noticed that the algebraic programmable Novus financier went for only 36 gollies, while the RPN programmable Novus scientist netted you a big 66. They are the same make, age and condition with comparable capabilities and built inside the same body. The RPN sold for almost twice the price. Now i'm not saying that a thing's dollar value equals it's real value but you were saying that RPN doesn't command a premium price. All i can say in response is neener neener neener! PTPTPTPTPTPTPTPTPTPTPTPTPTPTPTPT!!!

Note to everyone else: Joerg and me have been having this argument for about 7 years. I concede that TI sells more calcers. He buys RPNs to play with but not use. We both like beer. Agreement may never get any deeper.



Thanks for your nice comment - hope to see you at the next HP Conference ;-))




I may see you there again, if we ever learn where there is. Since you didn't ask for a translation of the "cheer"; i figure that you are learning Bronx-ese.
here's mud in your eye - db

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