[sharemywin]

I think they would do better by allowing groups to convert their group into a marketplace and add marketplace features to groups.

[lmm]

I think they've done that. Certainly I've started seeing a buy/sell tab in some groups.

[cableshaft]

I should have mentioned it's technically a marketplace group. That being said, considering most people wanting to trade or sell games put up like 10 games at a time and make deals for individual games with individual sellers, the price feature is usually superfluous (sometimes they go $9,999,999 just because).