Hi, Drew. Welcome to the forum. You can DEFINITELY do a lot with those 5 bills, homey, especially if you're willing to go used. If you go to Audiogon, most of the equipments there are well taken care of, b/c these audiophiles tend to nurse their equipments... way safer than eBay. I've used it to complete satisfaction, too.

For example, you can pick up this Cambridge Audio 540A integrated amp, which is very well regarded for $299... I bet you can maybe have the person include shipping in that price, too, if you want to cut some corners here & there. Entry-level Rega integrateds should be great, too, for your needs.

http://cls.audiogon.com/cgi-bin/cls.pl?intatran&1211626566

For speakers, you should consider Infinity Primus P162s, which you can pick up for like a bit less than $200, completely new. Even Amazon has them. Read Bob Reina's Stereophile review of these in the "Equipment Reviews/Budget Components" in this website. They sound surprisingly robust for small bookshelfs, great bass. I think the Infinity P162s are the cheapest speakers to get on Stereophile's vaunted "Recommended Components" list... PSB Alpha 1s and Paradigm Atom v.5s are well-regarded, too, but I'd go w/ the Infinity speakers if I were you; I was in a similar situation as you a few months ago, and I almost ended up with them. They sound damn good.

You can go Audioengine 5s, if you want self-powered, active speakers, but personally, I wouldn't recommend that route, even though that w/o an amp, you'll be able to achieve smaller footprint. You'd get a lot more from your music by having an integrated amp driving the speakers, plus more options when you want to upgrade. That Cambridge Audio 540A will drive most of the mid to high end speakers, no problem, when you want to upgrade from Infinity later. Or you can replace the Cambridge Audio with fancier integrated amp should you desire... see what I mean? If you go w/ Audio Engine 5s, you'll have to start over from scratch, rather than being able to upgrade piece by piece. And for $500, you'll have a beginner's audiophile system in place that you won't have to apologize for, that will knock the socks off anyone who visits your lair. So if you can make room for an integrated amp, you should do so by any means. And later, if you get a bigger place, you can move the system out of your computer into the living room or something w/o a hitch and have a dedicated hi-fi system.

I'm sure other members here will have more suggestions, too. I don't know how you plan to interface with the integrated amp... do you have a DAC? One cost-effective approach you can take is upgrading your soundcard to Echo Gina 3G, which would allow you to have digital-to-analog conversion outside of the PC box (great way to deal w/ PC noise issue), and also lets you hook your computer up to the amp via RCA. It's supposed to sound fantastic & you can get one for around $200, a lot less than what a quality DAC would cost. Good luck!