2 NL stories for you:
03 38 Powerplay- 30 hour salt water full submersion, no engines/drives sold for 30K, min. bid was 62K. Boat was a total loss. Guy in midwest slapped a pair of used 500's in it and got it running and was looking for 79K a few months later. Note the pics in the boattrader ad showed the boat underway yet the gauges registered nothing.....NL never indicated the boat was underwater or had any issues except the power/drives were missing.
04 Rinker 23 ft bowrider- my buddy bought it with no survey. Boat was 12k including taxes/fees. Takes it to a Mercury dealer and has impelller/all fluids/belts changed. Boat has a gauge indicated 21 hours on the 350/Bravo 3 (hull is faded, looks like 221 hours). In 15 months he has burned gas and a pulley only (bearing in pulley failed). Boat runs 46 mph top end and isn't a bad ICW cruiser.
If you look at what you are buying, do a little research you can score a deal. The Powerplay was a pig and wasn't worth 30K (much like this Donzi) but if you find a repo with nothing seriously wrong with it you can get a deal. If the boat is a name brand like Cigarette you will pay all the money though.....