I think this could be a very good idea if implemented properly. You haven't really gone into detail much and explained how exactly this system would work. Would these average prices be fixed into place or would there be a system which "reads" how much an item has been sold for on average throughout X time (e.g. a month), and give people an estimate based on those statistics?

I think this could be a very good idea if implemented properly. You haven't really gone into detail much and explained how exactly this system would work. Would these average prices be fixed into place or would there be a system which "reads" how much an item has been sold for on average throughout X time (e.g. a month), and give people an estimate based on those statistics?