I can't speak to the JBL's or Infinity's...never heard them or read much about them. However, my brother was in your position of having a really tight budget, but wanted some decent sound. He went with a pair of Polk Monitor 30's. At $200, I think he got his money's worth. They don't have a lot of extension, but most in this range won't seeing as they'll mostly have 5 1/4" drivers. I have B&W DM601's for my mains with an SVS PB10-ISD sub hadling the low duties, but I must admit, his Polk's sounded pretty sweet, even when comparing back to mine...and knowing they're only $200, how could you complain. If you want to stretch a little, a lot of people have raved about axiom's. I know you can get their M2i bookshelf for $280/pr. If it were me though, knowing that you'd want to add a sub to your bookshelf set up for more low end umph, I'd got with the Athena's. My local Best Buy sells 'em for $150 or so. They're built well, and have a nice neutral sound. I don't know what you can get for $150 that will even come close to them.
