I buy paint sometimes:
1 gallon of decent quality stuff costs $400-$600 just for the basecoat (1 gallon). More if its red.
Cheap basecoats actually cost you more: horrible color match, horrible coverage and bad mettalic control
1 gallon reducer for basecoat: $80
A gallon kit of clearcoat (reducer and hardener) is at least $200 for a cheap clear.
If you want the best premium paint like Glasurit or Sikkens, a gallon kit of clear will cost $500 alone. Sikkens is what Otto's collision center uses.
So far you are: $680 just for materials alone, not to mention the labor.
BTW you did not happen to use rattle can primers did you? They are ok for small spots, but 2K primers (catalyzed) will have more build, less shrinkage and better rust protection (epoxy).