Wow. That sounds painful. Here's my $.02:
1) Skip lunch for a week or two. Basically, save up $40 to $60 for a GPU.
2) Familiarize yourself with the Radeon cards here:
https://en.bitcoin.it/wiki/Mining_hardware_comparison3) Look for something like the Radeon HD 4870 on eBay or Craigslist
4) Do NOT overclock it until you've banked enough BTC for a real GPU