I have read through a lot of these posts and have found there is a general consensus that people hate it when prices fall on the market boards based on undercutting. While I agree that it's a pain in the behind, that's just how any economy operates based on supply and demand. That being said, here is a change that SE could make that I think would help. First thing I would do is show an average sale price based on the last (5,10,20, whatever) sales which we can call the base price. To get people to hold or raise their prices you just adjust the fee schedule. If you sell at exactly the base price you get charged fee x, if you sell below the base price you get charged an additional % on top of the regular fee, and if you sell above the base price you get a discount on fees. Thoughts?