Good luck.

It sounds like you don't have a lot of $$$ to plow into this, and you might not have the time and space to mine the Make-It-Yourself forum for ways to make your own gear. Under the circumstances, trolling for bargains on Craigslist may be the nearest equivalent to nabbing stuff from a garage sale.

The first easy, cheap way to cut down on weight and expense is to take just exactly the right amount of clothes you need to stay warm and dry, with no backup clothes or extra clean clothes. WHat you don't bring is the lightest (and cheapest) stuff in your pack.

Workable clothes can be had for cheap. For example, you can get some fleece from Goodwill, if you don't have any. Other stuff, too.

A second easy, cheap way is to make an alcohol stove and use it. There are at least a dozen DIY models you can make from such stuff as soda cans or cat food tins.

P.S. Don't turn your nose up at your 30 year old gear, if it still works. If your old pack is comfortable but ratty, spend the money on other stuff first. Like a decent sleeping bag and sleeping pad.