It's all about lycra. I own 3 pairs of lycra shorts, and I'm thinking about going to bibs (stay in place better, from what I hear). I thought bikes were expensive. As far as jerseys go, I'm not such a huge fan of wool. It's a little warm for me (I heat up), and LA isn't that cold to justify it.
Shorts + knee or leg warmers are pretty much all I can stand to ride in unless we're talking under 15-20 miles. Sometimes I toss on a tshirt, but I'm trying to build a collection of decent jerseys since it's so much more comfortable to ride in them.
Plus, wearing them to bars/shows pretty much guarantees a "cute butt" compliment from a girl (or sometimes an enterprising guy)!