Having watched as an Autavia GMT went for over $2300 on ebay last night, I am convinced that maintaining any sort of pricing information or database will be virtually impossible. (I had swapped e-mails with the seller, and given him an estimate with $1200 at the top of the range.) When two guys want to win an auction, regardless of cost, it is difficult to reach conclusions about how this affects "market values".

My suggestion is that we keep this relatively simple, as follows:

• we would add two columns to the reference tables, one for relative scarcity and one for relative price; we can do this slowly, over time, based on input from this Discussion Forum, if people are so inclined.
• the relative scarcity would be an estimate of how many we see on the market (ebay and dealers), per year. we can call it Offered Per Year, Available Per Year, etc.
• the relative value will be some approximate multiple of an established standard (for example, a three register Carrera, white-on-white, Valjoux 72 might be the standard (set at 1.0), so the Monaco, white-on-blue, Cal 12 might be something like 2.0 to 3.0).
• all this would be very approximate, with clear disclosure that it represents only the opinion of one collector (or one small group of collectors) and that the values vary considerably based on condition, extras (box and papers), the market, etc.