[tbirdtbird]

you'll need at least 2 gals of single stage per car. Mix those 2 gals together in a brand new super clean 5 gal pail and then pour back into the gal containers. That way no surprises later on color match.

with a quality color product with high solids you should only need 3 coats of color. Cheap paint tends to be watery and doesn't cover well; you'll use more, diluting whatever savings you thought you had made

most use grey primer, way easier to cover than black

60 bucks to match is a rip since they just shove your part under a scanner. Local paint suppliers do not charge for that service. Maybe cheap isn't so cheap after all.

finally, if you ask, most all local paint suppliers will give you 10% off. Nothing off if you do not ask. Remember the markup in car paint is 300%