THIS. I just graduated and really wish I did this. Spent so much money on shit that nobody cared about and I ended up hating/giving away after a while.
OP: it would be in your best interest to search out the thread mentioned and read through the whole thing. You can get by very well on very little if the pieces are well selected.
OK. If you're on this forum I would really hope you're not here because you're trying to impress other people. Yes, fashion is always to a degree an ego-stroke in front of others but don't you consider it a personal artistic interest as well? I'm certainly not the first in this thread to say it but most people in general don't care that much about what you're wearing and most of those that do will probably think you're pretentious. While it can be expensive, college students often spend their money on stupid shit anyway...like really stupid shit (not even talking about drugs or alcohol).
If you have to choose between spending your money on clothes or partying and you would prefer the latter then by all means go for it. It just bugs me when people suggest that college should be this one concept of constant debauchery though (what school did you people go to anyway?). I think that can be fun too, but what do you really get out of it in the long run? "Yeah I partied so fucking hard in college...it was awesome!!!" These are the type of people that always reflect on the 'glory' days (that really weren't all that glorious at the time but they have selective memory) which they consider the peak of their life.
I'm currently an undergrad and I really enjoy clothes, and I know there are plenty of others on here in the same boat. If all you want to do is dress nice to impress other people you can follow some boring formula and yes people will notice and may be a bit impressed but overall won't really care. If you actually take interest in clothes then I think you'll find it more fulfilling of a pursuit. My two cents.