Out of curiosity, just how "accurate" would you guys say the price estimator for pinball machines is here on the pinside archive? I haven't owned a published price guide book in a few years, so comparing values isn't really something I have done.
As an aside, for anyone who has interest in video games (home console video games), theres a nice website that takes aggregated prices from various websites (amazon, ebay, etc), and compiles them into a neat little graph and an approximate value for different conditions. It shows value trends through the years and months, and its a pretty neat tool for collectors, buyers, and sellers. Of course pinball is a more "niche" hobby, but implementing graphs and trends into pinside would be a welcomed addition, I'd think.
Here's the video game pricing website for those who are interested: http://videogames.pricecharting.com/