I have to disagree with those who say that cheap cars do not happen anymore. I have a Honda Crx that was given to me because a lady wanted it out of her yard after her husband died. I had to replace a few parts and put a couple new gaskets on the engine, but nothing has been rebuilt. I had about $700 invested in it. It may not look like a new car, but it has been extremely dependable for almost three years (has over 200,000 miles).
I know that this car is tiny, but I just wanted to give you an example that they are still out there, you just have to make sure everyone you know keeps an eye out for you. In your case, I might consider rebuilding the tranny, while checking craigslist on a daily basis so you can purchase another car for a backup.