HA! That's easy
Two of my friends and I went together and bought a black '78 X for $150. ($50 each) I knew the car and knew the problem with it but the owner was moving that day and had to get rid of it. So I took a timing belt with me, installed it and drove it home.
The three of us then autocrossed it for a full season doing nothing more than changing the oil. At the end of the season, one of our triad bought out the others and drove the car as a daily driver for several years. Other than regular maintenance, he didn't spend much of anything on it until the motor burned a valve at about 250K miles.