My philosophy for automobiles is simple. For every $100 paid for the car and major maintenance, the car has to last 1 month. I bought my son a car for $900 after graduation. The total maintenance bill was about $700 including tires over a 2 year period.
You can get a fairly nice looking, fairly well maintained car in the 100k mile range for around $1,200, and insurance is cheap! For 20 years of married life, I carried from $500 to $800 per month in car payments, because my wife couldn't be seen in a beater. Now we are broke. You do the math.