For Unreal Tournament I have a small job to offer - about ten custom sounds, mostly weapons have to be replaced.
It is actually for one map which will have some of my own sounds.
3 freelancers are bidding on average $55 for this job
I have done this with NFS to some extent. Played Unreal sometime back. So I ahve a fair Idea of the game and how to do it. Preferrable that you provide me the game. Or will have to look for one here.