Since money seems to be a factor - look at travel costs also. On the T/C Explorer you fly into and out of Provo (PLS) and the crew meets you at the airport. We paid $10pp for the van ride to the boat and were able to fly in and out thru CLT the same day. Do get on their mail-list and check for specials - we saved $400 pp. a couple years ago. Also all cabins are ensuite and anything main deck or above is beds not bunks. It's bad enough sharing with a stranger w/o have to crawl over them at night. Big cabins also, our main deck had a full size bath, (short shower but I'm 6'4") 2 single beds, a nightstand and a corner desk.
On the Saba/St Kitt's itinerary you buy a flight to St Marteen and from St. Kitts (or the other turn) and that must cost more. Also there can't be as many flights from St. Kitts either.
A third option no one has mentioned are the mid-range sail cats in the Bahamas.
Cat PPalu often sells extra spaces if someone charters most of the boat - last I heard it was $1700pp. Plus the flight to Nassau.
Similarly
Lost Island Voyages - another 60ish' sailboat out of Nassau. They seem to have a more limited schedule.
Or there's Juliet out of Miami to the Bahamas. Some of their cabins are ensuite now.
One Vessel – Multiple Destinations