It looks okay since the ps3+dual shock is about $450 and the xbox+3 extra controllers is around 480. Also all of those games have multiplayer which is what you want. Then you can get LIVE and play with your pals halo 3 vs other ppl.
I would not go for it. I think if you trade for a 360 and get a RRoD you are not covered by the warranty since it goes to the first owner. You should check this out first.
I had no problem with it. I was using an ISO not a CSO. Do you still have the mms files in the stick? When I played guitaroo man it lagged with the files, then I formatted it and worked just fine.