I saw a 1996 Catalina get demo'd last week because of massive delam on its keel. Had regular maintenance, but they just don't (or didn't, in 1996) get their fiberglass situation figured out.
My vote, and I often am not in keeping with popular thought (I dumped my roller furling yankee and put hanks back on it, as an example) would be to look into a westsail or cheoy lee; something with a larger keel, heavier displacement, and reduced sail area.
Here's $10K for a cheoy lee. Same deal as any boat though, you want to inspect every inch of it and make sure it's what you want. But I'd rather have that $15K for repairs and upgrades, rather than top out your budget right on the boat price.
1972 Cheoy Lee Offshore Ketch Boat For Sale
You can get the sailplans and some advice from Robert Perry on the cheoy lee's as well; he's google'able.
I had some light displacement boats before (an Ericson 32 as one of them), and in rough stuff (like is common in the gulf stream), having a bit more weight down at the bottom really helps.