i dont like your color pallete. i think a good free resource about this is Sacha Greif's Colory Theory ebook. the "buy.sell.trade" banner is uglu, too big and useless. it seems that you've adopted a flat design style, but in the product page the "cash/trade" button is 3d. i love that it has keyboard shortcuts. but i cant figure out why you have such selection of shortcut. for example why search is #? i think / is more appripriate. or why list an item is D? shouldn't it be L? the same thing for categories. and the simplicity is awesome.