I wanted to paint the lower half outside with a rubberized paint (not black)--but it was only
sold in gallons at $60 per--which might've been okay, but the shipping was close to $60 a gallon also. Today, it might seem worth it, but in 2015 we had so much to do on Peanut we didn't rubberize it against rock chips. So far, no major issues with chips yet.
Depends on how the paint is
sold. Some paints can be had in very small containers indeed. The rubber paint I was looking at back then only came in gallons. AND it wouldn't keep once opened. If you had some left, in a month it would've hardened and been useless for touching up.