I'm a broke-assed roadie myself, but take it from me: you do not want to skimp on the shorts, dude. I've got a cheap helmet that cooks my head like the Boston Kitchen, an old donated jersey, Sora components, 10-year old cycling shoes, old SPDs, recycled Gatorade bottles instead of those nice insulated water bottles, gotta pack pop tarts instead of gels for long rides, and the last upgrade to my bike was handlebar tape, but I'll drop $100+ on Pearl Izumi Elites because...man, that's my crotch we're talking about.
Think about it: do you really want to go cheap on the thing your nuts are resting in?