From experience of talking to fellow cruisers, if you stay in the Miami area there are bucket cruises to be picked up nearly every, day and week, and cheap.
Think about it no airfair, can take a last minute deal at a couple of days notice, as your retired etc etc. Brilliant, if you can say "Who's sailing and whats available"
Clients such as this will not normally put the $ per week profit into the line they would expect from you or I, but it is a margin and a "bunk" filled.
You know better than that pebbs, cruising never gets boring, different people to play off again by the week and if you are so lucky, you can plan it to explore more in ports you may have seen a dozen times.
Personally I spent $3000 to be on a cruise out of Miami. On it I met a fantastic retired couple, who through bucket did it for $800 (Miami based). They had a theory that it was cheaper to do this once month than be at home, cant prove it, cant deny it.
But boy do I envy them for staying in the Miami area