Not to belabor the point but philatelic prices follow no formula.
The second point is that I do not usually actually forget something, it just takes time to shuffle through the flotsam and jetsam. The dealer conversation that I overheard I believe was about the new AAMS catalog volume 4. Someone at the AAMS was showing the dealers the prices that are to be found in the new volume. These dealers thought that the prices for many FFC's were much too high compared with what gets sold on the market.
Keep in mind there are some rare ones. Those go for high prices. However, sometimes two guys want a particular item that is not really rare but still kind of hard to find and they may butt heads at an auction.
Hope that helps.