i sell on gemm every day, there are various options a seller can choose but the bottom line is, what you see as the price when you buy is what you pay plus postage and packing as stated on the sellers gemm page. gemm does take a % of the sale price directly when the item is paid for, but not of the postage and packing cost. i often mail people if i know them, they are buying something 'expensive' or multiple items to let them know its cheaper to deal with me direct. all in all, i think gemm is easy to use, works well, and the feedback from gemm if there are any problems is very quick and you get a human mailing you not a machine. very few problems with them though, or any of the buyers or sellers, much prefer to ebay myself,
cheers Sutty