First off, 10k for a car is almost impossible today. I would say 80% or more of the cars being bought today are at least 20k or more by the time you pay for everthing (taxes and surcharges).
You too are both looking from the wrong angle...
1) penguin, being young, is prob refering to a used car as that is all he can afford
2) flight17 is referring to a new car.
I can say, that I have had old cars where the transition went out, and I just got rid of the car. Why? because as penguin said, it was more expensive to fix than the value of the car was worth. Granted it was 16 year old car with 100,000+ miles on it, but his point is valid. That being said, if the transmission went out on a 2 year old 50k car, I would fix it (then probably sell it).