Ah, I used HRK before. I don't know why I stopped doing so, maybe because of my huge backlog or because I didn't get a game I really like from it. (Except Street Fighter IV?) I like how their trading system works.

There's a similar site I'm not sure if I should recommend because buying these games is like gambling so I'll self promote my "Games for SBD" shop here: @ahmadmangalists check it out if you have time.