Re: "You make your money buying the boat, not selling it."
ahhhh ... I know this one.
It is better to buy a boat which someone has already spent money on than to buy one which you intend to "fix up". It's the same as classic cars ... the money spent restoring/upgrading them is only fractionally recovered in the eventual sale. It is thus much better to spend a bit more money on one which is already fully tricked out, than save a bit up-front but spend lots of time and money making it "just right".
Ask me how I know this ;-)