One of the things that experience has taught me (over and over) is that you cannot cut corners, you can only polish them correctly. I know a lot of people think I charge too much (fair enough) because I get atleast 1000 for most paint corrections, but again, my experience has taught me that it takes time (and a lot of it) to get true results consistently.
So the problem arises, the client only wants to spend so much (say you charge 50/hr and the client wants to spend 300). This limits you to two steps (time wise). Do you hit hte paint hard with a compound and try to finish it down (running the risk of having a lot of garbage reappearing) or do you do two milder steps that will not remove all of the deeper defects (but will help protect against hologramming)?
I cannot answer that because I struggle with that situation daily, but keep in mind it takes time, patience, and experience, and MORE time to do the job correctly. There ar no short cuts.
I would probably do two mild steps and not take any chances. Sometimes we shoot outselves in the foot by trying to do too much. If perfection starts at 500 (or whatever) then for 300 you are going to get much less then perfection. Why should I risk my reputation because I am limited (by whatever factors) on the time I have.