$0. Went to the University of Texas. I always had a full time job in college (first on the ramp for a commuter airline then as a flight attendant for a certain Dallas based airline). I got two Pell Grants that covered a couple of semester's worth of tuition.
I only got a certificate or rating when I could afford it. I would save up the money and then go the the local Mom and Pop Part 61 school and pay cash for the training. Of course you could rent a Cessna 150 for about $28 an hour back then so flying was pretty cheap.