Bought a cheap spray rig from an online auction and it cost me way more than I saved

I picked up a used HVLP system for $150 thinking I got a steal. The compressor looked fine but the gun had a tiny crack in the fluid tip I didn't see. Tried to spray a lacquer job on a dining set and it sputtered orange peel all over the place, ruining the finish. Had to strip and sand four chairs and a table back to bare wood, which took two full days of extra work. The replacement parts for the gun alone were almost $80, so my 'deal' turned into a $230 lesson plus lost time. Anyone have a good way to check used spray gear before you buy it?