Definately check out play it again - it's rare, but sometimes they'll have a good set.
Also check with any colleges around to see if they'll be changing equipment soon - again, not a sure thing, but sometimes they'll unload stuff for cheap.
The main thing to worry about with the bar is that the collars rotate well. Read up a little on bar maintainance and you may even be able to keep an inexpensive bar working pretty well. If it doesn't rotate well, your wrists will get shot to hell.
I'd also recommend buying one big pair of decent bumpers and using regular smaller plates (35's) to add weight. Unless you're gonna be cleaning in the 250-300 range, then that becomes impractical.