For a real low cost paint try this urethane
Any color for less than $100.00 a gallon with activator.
I wouldn't use their enamel, and I don't know about their clear.
But I've used it on my car and boat and it's the toughest stuff
I ever used. It's held up great.
I also clearcoated my car with SPI universal clear.
That's a great combination.