How much do you want to spend,and do you have the tools?
The cost of materials can go from 5-20 bucks for rattle can
up to 1,000 for like House Of Kolor,Kameleon.House Of Kolor,and Metalflake are about all I use.You can do a 'Flake paint job for 300-400 in materials.
The work is in the prep.Sand out any nicks,scratches,etc with 180-220 paper.Use good 2 part primer.Block sand,reprime,spray a LIGHT coat of contrasting color(of the primer)and block sand until all of the contrasting color is gone.Clean parts with soap,and plenty of water,dry,wipe with tack rag spray your base color(if doing any art work{flames,pinstripes,etc.})mid coat clear,then your art work,candy,etc.Then final clearcoat 3-5 coats.Let sit for 3-10 days wet sand with 1,000 grit paper then 1,200-1,500 then 2,000.Then buff with a buffing compound then with polish compound then hand rub with a handglaze.
This is just the short explination.