Purchase advice; building home server

Greetings and salutations!

First and foremost I am a Computer Science major! Secondly, this is my first post. Anyways here's what I've got.

Home server uses: Hamachi VPN, Streaming recorded television, file server, hosting a steam server or two (think Left 4 Dead 2, Counter-Strike, Team Fortress 2), it will be on 24/7 (or as much as possible), and maybe a small website.

Power usage requirements: I need low power consumption and a relatively quiet case and components; while not sacrificing on necessary performance. If quiet isn't possible, low power consumption is a higher priority.

Current network setup: My room houses the main cable modem, and wireless router. The router supports DDSN (but only DynDNS which is $20/year) which is what I will be using to get around our dynamic IP address. The download speed's average about 10mbps-15mbps and .95 mbps Upload speeds, I have two roomates who typically only use the connection at night time.

I am pretty interested in some sort of SSD to house the main OS (something small, like 64 GB's) and a larger HDD for data.

My budget would preferably be around $250-$300 but I can go beyond if necessary; I am going to be using consumer grade components. However, I found some used servers on ebay e.g. http://www.ebay.com/itm/Dell-Poweredge-840-Xeon-X3210-2-13ghz-Quad-Core-4gb-500gb-CD-/290855747413?pt=COMP_EN_Servers&hash=item43b85a7f55 if this will satisfy my needs I have no issues buying used (except these don't seem to take SATA III or SSD's from first look).

Thanks for any help the community can provide! Constructive criticism welcome; I don't know everything! :)

Building somthing new for that price range would be hard, especially using actual server grade equipment. You might be better off checking your local craigslist for businesses or schools that are selling off their old servers for bottom barrel prices.

What did you think of the eBay link? I'll look into Craigslist, thanks for the tip!

Hmm, not too bad for the price, memory is the one thing that you'll need, hosting so many things. So it might be worth it to look for somthing with 8gb.