i looked into making one with a scoop like the subaru wrx's have ($50 - $250) and some vinyl wrap ($100?) - doesnt seem that difficult... but i never did so what do i know
it seemed to me that the stick on scoops are cheaper than the ones you have to sand and paint but they look really junky - i was thinking a stick on with the vinyl wrap would make it look more professional - like it was molded as one piece