Probably the best bang for your buck is going to be older, used gear. Search these threads, maybe audioholics or something like that too. Ebay can be a great place to find bargains, but here are two that most people don't look at as frequently: garage sales/flea markets and bulletin boards.
I found a pair of Sennheiser HD 540s at a flea market here in Germany, and I paid about $20 US for them. I probably could've paid $12 or so (10 Euro) but I felt badly; I guess I'm not the best at flea markets. But a lot of turntables, receivers, speakers, etc. *may* be good. Read around and shop around, and you'll learn how to avoid crappy products. I'll check my bookmarks later and PM you some info.
Also, college students come and go all the time. Check bulletin boards in dorms, near doorways of major buildings on campus (student union, etc.), and in similar places. A lot of times, college students who either need money for beer and bread or are moving and don't have any storage space will get rid of pretty good gear for dirt-cheap prices. I've seen a decent pair of Logitec speakers for $20, and these prices are negotiable too.
The more you look, the more people you ask, the better your chances of putting together a nice system for very little money. Keep in mind, too, that at garage sales, for instance, people with more money are more likely to have bought good gear and have no idea how much it's worth. One garage sale I went to had some nice Paradigms laying around for a good price; the owner thought they were a nice brand but never used them. Good luck, and enjoy the music!
