I have done a lot of DIY in the Bahamas and Caribbean. (and the Keys too).
Sometimes with success, most times not so much! A lot has to do with the fact that I am not that great a flyfisherman and also with the factor of luck.
For instance, I once found a spot where I was catching baby Tarpon and Snook
so I booked another trip and never saw a fish! Same week .... different year!
Also tried different weeks but never duplicated the first trip.
I think the best way to cut costs and have success is to join a group going to a particular spot like the Acklins group going from this site.
Like you I would prefer to find a spot with both small Tarpon and Bonefish but I have found you would be better off choosing one fish to key in on and find a place to hunt for those.
Don't want to discourage you but it is pretty tough to hit all conditions correctly and have success then again win or lose I always keep trying.
frank in Nahant, MA