Or you can take the data from pinsiders that added or sold their pins in their profile. There is a section in there that asks how much you bought or sold it for. Even all the flippers and spectators around can't really mess with those numbers much. You can also build a threashold that takes the average price and will only take data that is (lets just say) +/- $500 from the average selling price. This would control sudden large drops or gains in prices. Flippers can't inflate the price and buyers can't dump it. Only way pin prices go up and down is on a gradual scale. There was also another post last week about how pins are sold in very difference prices when you compare east coast and west coast prices. Maybe that is also a good way to separate that data. everything east of the rockies and west. You don't want west coast prices to drive up pins and east coast prices to drag down. "guestimates" are just that a guess. This I think would be a better way in gathering real data of pinsiders transactions. Pinside is one of the largest pinball forums around. I would assume that what we put in our profiles for sale and buy prices are more accurate then some guy that found a pin in dads garage and puts it up for $10,000.