What I would do in your situation is:
(1) check Goodwill and other thrift stores in your area for a working vintage machine. They seem to be available in spurts where I am. When I can find one, the cost is usually around $35 or so. Check to make sure the cords are supple; you don't want really old cords or frayed cords. I usually test first by manually turning the hand wheel, just to make sure that the machine isn't frozen. All places have electrical outlets; you can move the machine closer to an outlet to make sure that the machine runs. Bring your own thread and fabric (and generic needles and wound bobbins, if you like) to test that the machine actually makes a stitch when you turn the hand wheel. I also usually fiddle with any knobs and levers a bit. Know the return policy of the shop you are in; the best places to shop allow returns with a receipt within 7 to 30 days. One thrift shop I know does not allow returns on sewing machines, so at that place I do extra testing within the store and usually take only really inexpensive machines. Often cabinet machines are a better buy than portables, simply because fewer people want the challenge of the extra weight of a cabinet and the difficulty of transporting it.
(2) Check out the Brother machines at Walmart. These machines tend to run about $100 to $250 depending on number of decorative stitches. Many quilters on the board here are happy with these machines. Be sure to try it out immediately. Walmart is very good about taking a machine back if you don't like it.
I suspect feline fanatic is correct about the belt(s) in your old machine. If you absolutely love this machine, I would keep it and wait until I had more money to take it in to a repair person -- explaining about the history with timing and asking for replacement of belt and anything else that could be causing the problem. There is no guarantee, though, that this will give you a reliable machine to work on. That's why I would look for another machine first.