if a boat has less than 50 hours on it.........

over.......6 years what should you look out for if purchasing...if anything?

Rust, water in oil, corrotion on electrical components.. Is winterization an issue? If so, check all hoses, bends and such. Both cooling and exhaust.
A lot of boats deteriorate due to not being used enough.. Imagine your car sitting there for 6 years, every rubber component would be hard and in need of change.
Apart from that, if it all seems ok and the hull looks good i wouldn't let it ruin a good deal
Good luck