|Re: HP vs. TI on eBay auctions|
Message #5 Posted by Michael de Estrada on 19 Apr 2010, 11:31 a.m.,
in response to message #4 by Maximilian Hohmann
Statistical analysis is only useful if it places proper boundary conditions on the model. Regardless of rarity, if the population of buyers that are willing or able to spend 6 to 7 figures on a collectable item is zero, then that particular item can never attain that price. Rather, I see the RPN attribute as an added factor to the relative value of the calculator, rather than an absolute determinant. Also, I see the population of calculator collectors for whom the RPN attribute is important to be very small relative to the total population of collectors. Some, such as Joerg, may even see it as a negative.
Update. The auction is over and the National Semiconductor 4615 that was advertised as "RPN" sold for $86, whereas I paid only $13.45 for mine, which was not described as "RPN". However, I am not suggesting that it is the only reason for the differing prices, since other factors such as a worldwide .vs. domestic sale and the fact that this seller (datamath-computer-museum) gets tremendous exposure when compared to the typical calculator seller. Still, I do contend that there are sufficient data points for other similar sales to conclude that there is a positive correlation between RPN and desirability/price. The same, of course, can also be said for Hewlett-Packard .vs. all others, and a non-HP brand RPN will probably never achieve some of the prices paid for the rarer HPs. Still, some vintage HPs such as the HP-45 are pretty much common as dirt, and can easily be found in good condition for under $100. The APF Mark 55, BTW, went for $128.50.
Edited: 19 Apr 2010, 5:55 p.m.