Where do I buy lacquer with the best price/performance ratio?

Hey guys. A neighbor across the street bought a rather run down Schwalbe KR 51/2 at Ebay and literally said to me: “Can you have it when you get it ready?”. The condition is this: -Black, sprayed with spray can body parts (the previous owner did not make a “hold” before the exhaust -.-); -Frame actually fully in order, as far as I can remember; -Replacement parts wanted to buy the neighbor. I now have the question as to how I use the paint on the I know that I have to degrade and grind everything before, after grinding: What do I prime with? Which is the best top coat? Clear varnish about it? Spray or roll? What color tone? I thought that the original color would be best, so something towards egg yolk yellow. Is there any color tones in this direction that I should not take in any way, because the result would be “ugly” in good German? That’s what I would like to get away with. Dear greeting from my side.