Hmm...
Well you might keep an eye on
www.marinedepotlive.com or
www.tropicalfishoutlet.com as they sell supposedly captive-raised Bimacs.
Saltwaterfish.com and Liveaquaria.com also have both had octos in-stock frequently as of late, but those aren't going to be Bimacs. Saltwaterfish.com sells O. Filosus/Hummellincki and Liveaquaria usually sells Aculeatus abdopus (indo-pacific) No idea what their Caribbean species is, but the picture looks like a dwarf O. mercatoris. Since they do suggest a very large tank and say it can reach 30 inches, I would assume they do occasionally sell O. vulgaris.
Several species make good captive pets, and the Caribbean species don't require a chiller, unlike Bimacs.