I'll echo what's already been said, and I'm the guy who DIDN'T take that advice. I bought a boat that seemed like a steal.. paid about 1/2 to 1/3 of what my boat may have gone for if it had been in excellent condition. Figured it didn't need a TON of work.. just some cleaning up, and the odd repair here and there. The hull itself is in good condition, the standing rigging is sound, sails are pretty tired and stained but usable for now.. why pay twice as much just 'cause another boat's prettier, right? I'll have fun learning how to work on boats, and save myself a couple thousand dollars at least, right?
Wrong. Between the purchase price and the money I've sunk into some hidden problems in addition to the known problems, I've got more money into the boat than I would have had I just bought one of the top-dollar examples of my boat. I've also got well over 100 hours of labor into it. Of special note is that fact those 100 hours could have been spent sailing, but were spent fixin' to git ready to sail instead.
I'm not complaining as much as it sounds like I am... to be honest, it's been a labor of love (but not always fun), I've learned a ton, and it's a real feeling of accomplishment bringing a beautiful boat back to life after seeing it neglected for years by it's previous owner. I'd still rather have been sailing.
If you like to fix stuff more than you like sailing, then maybe the current boat you mentioned with some mushy spots in the core is for you. Pay next to nothing for the boat if you go that route. You'll end up spending the money in the long run anyway.
Good luck! If you do decide to tackle the project, make sure you post some pics... I want to see folks having as much fun as I did!