A guy down the street from me bought a brand new boat. The wife didn't like boating. It sat beside the house half uncovered for 5 years with very little use. It looked like crap.
Then one day I see him power polishing, with a friend inside working on the upholstery. Then they changed the oil (probably the first time). On and on. Then they put it in the garage.
I saw the ad in the paper - showroom condition, always garage kept, professional maintenance, yada, yada. It sold in 1 day. I bet the stringers were already half rotten.
You never know. Buy new, enjoy the warranty, take care of it and it'll last a lot longer than 15 years. I know, I know......depreciation. Truth is depreciation is the cost of personal satisfaction and peace of mind.