If I were looking for a deal on cheap gear, I would start by having a list of sleeping bags I would be happy to own, and then patrol ebay, craigslist, thrift shops, and yard sales until I found a used one at price I could afford.
I started backpacking with a tube tent and a synthetic bag that was chilly at 32 degrees. But I was young, a little bit stupid and stubborn, and made it work. You can get a ton of usable equipment at thrift shops and the like. But if there is ONE piece of equipment I would want to make was sufficient, it would be the sleeping bag. Packs are a dime a dozen, tents can be tarps, stoves may not be necessary for all foods....but if you're cold at night, you will not have fun.