decent price. I have seen them as low as $99 for decent guns. The compressor however is a big part. I have seen people try to paint with smaller compressors and it has ended both times in problems.
The main issue if that when you lose pressure and it kicks on, its sends a small surge, that disrupts the correct pressure in the gun and many times leads to a small "drop" of the paint instead of even spray. Thus you get runs much easier in this circumstance.