Re: Mason 43 for under $40,000!
Thinking about it, the Masons have teak decks. They fail at around 30 years. There's $10,000 right there. That's if there is not major core damage. Core replacement will about double that figure. Figure a year of your time to repair just that, if you DIY. A beta marine diesel is $14800 for the 60 HP. model and you're just starting. Woodwork, fuel tanks, standing and running rigging, and the other items mentioned by the other posters. Under 40 might be no bargain.
"Ulysses" - Alfred Tennyson