The only criteria to sell anything is price. You could sell a sunken
boat for $1. The trick is to find a diamond in the rough. One you like, but needs a bit of
cleaning.
I'm not saying you should buy a derelict, but if it just needs new covers for the
cushions, a little wax, a couple of new hoses - those are all minor issues. The expensive stuff includes
sails,
rigging, engines and sail drives. If any of that needs replacement/repair, the price better reflect it or have the seller replace it before the
sale.
If you've scored a great deal on the
boat you love, you'll still be ahead if/when it's time to sell and you get market price for it. Apparently 20 yr old cats sell for more than when they were new, so buy a 15 yr old one, enjoy it for 5 yrs and make a profit.