Get a cheap wireless router
(i know your in college, but you dont have to plug it into the internet of anything, just connect it to the power supply so its emitting a wireles signal) then plug in a cheap network hard drive, (any external hard drive with a LAN port) and away you go
🙂
I have this network hard drive:
http://www.freecom.com/ecproduct_detail.asp?ID=3402&CatID=8020&sCatID=1146195&ssCatID=1146196
If your looking for something like Apples time capsule, which is basically what ive just described but the wireless router is glued to the external hard drive then you wont find anything cheaper than the Time Capsule, Sorry.