Censored,
It depends how "gay" you want to get, i.e. do you want to go like full on metro/fashionable, or just like passable not a slob. If the former, you'd need to spend more. If the latter, i would just get like 6-8 outfits from like banana republic/the gap/old navy consisting off
-dress pants/fancy wash jeans
-long sleeved dress shirt
-colored undershirt, that matches, but is not the same color as dress shirt
-2 pairs of dressy shoes, 2 belts, one set black, one set brown
and your done. You can easily do this on your budget, and shopping entirely online as well. If you want to take another step up, get some kind of blazer.
I'm really bored, here is a potential outfit:
http://www.gap.com/browse/product.do...amp;pid=315674
http://www.gap.com/browse/product.do...amp;pid=329311
http://www.gap.com/browse/product.do...scid=347026062
http://www.gap.com/browse/product.do...amp;pid=308988