The championship which gets you the best lap to money ratio is the amatuer european championship. In this championship you can get 350000cr form 4 races of 3 laps. To do this you race the first 4 then save (before you go onto the last race) then quit the last race. To get 350000cr you have to win the vertigo racecar. Keep on loading until you get it and then sell it for 300000cr.