These would be what I would build if I were to rebuild my comp today. Total cost is $831 with the 6800gs or $1081 if you get the 7800gtx.
You can get cheaper RAM if you got 4x512mb dual channel sticks and you could probably save quite a bit if you got the value series and don't plan on overcloking at all.
Also for Case and Power supply I don't know very much about so I can't help you there.
i dont realy have a budget.. im just kinda picking things out i like and and saving, getting others to buy for me. but in total i guess no more then $1,500.
were did you get that 3k from? oh, from my 1st post, dunno if u dident read it all or something, but that is a computer im basing mine off of. its the ultimate gaming machine for the show - attack of the show on G4.