I should point out that if the design requirements or expected usage were different then I would radically change the boat. Assuming that I might cross the Atlantic once to do the med is one thing, if I was planning on a real ocean traveler then I would be looking at better founded boats. Larger euro styling boats like the Beneteau would give way to smaller and older Amels, and Oysters.Less than $15,000 - i wouldn't. Not that a boat in this price range isn't capable of crossing oceans, but I wouldn't be on one while it did.
$50,000 to $70,000 range - what we have, a Beneteau 381. It falls nicely in this range, and with some tweaks I would feel comfortable with it. The quality may be a bit lower than I would like however.
$100,000 to $130,000 range - something newish, European, and larger. For this trip definition I don't see the need for top flight quality, but the extra budget would allow a larger and better equipped boat. Possibly a 381 again but with more toys.
$200,000 to $250,000 range - mid size catamaran. Newish with toys. Knowing me one focused more on performance than load carrying, but likely a mix of the two
$700,000 + range - how much + is there? My dream boat of the week is the Neel trimaran at around $600k for the 45. If there is a lot of plus then the Neel 65, maybe a big Gunboat. If there is an unlimited amount.... Well I was going to say a Gunboat 90, but frankly I think it would be too big. It would probably come down to the Neel or a big GB.
The Carribean just doesn't demand the same type of boat that the North Atlantic does. When budgets get unlimited then you buy whatever you want, but most fair weather sailing doesn't really demand than much in terms of absolute quality. A Beneteau/Hunter/Catalina for the Carribean is perfectly fine. Given a fixed budget I think the money is better spent on more and better living accommodations than a stronger design... At least so long as the boat is strong enough to do what you want it to do.