i would definitely recommend doing it yourself, especially since your car is dark color, so even if you dont do that good of a job, it would not be as noticeable as say a white car or my colored car.
honestly, just keep on sanding till you see that the surface is flat (no texture), then apply some primer, and sand that as well so that its smooth, then put on paint and clear.
the whole project cost me under 30 bux, and i figured if i mess up i would take it to my paint guy (he said $90 would do it) and do it that way, but i am pleased with the results so they stay and i spend the other $60 on gas
give it a shot man, dont be scared, its just paint, if u mess up take it to a body shop