A cruise is nice, inexpensive and very relaxing.
You haven't said when you'll be going, but given the damage throughout many islands Caribbean, something down the east coast of Mexico might be nice and you can get one of these cruises from Tampa, which is a nice port to depart from.
Another possibility is a departure from New Orleans, since the trip down the river to the Gulf is really awesome.
Save Hawaii for when you can afford it well enough to enjoy it with no worries.
As others have noted, it isn't a budget friendly destination. It would be cheaper to visit Europe.
Finally, no part of Florida is anything like the Caribbean and we've spent enough time in both that I make this statement without any qualification.
Mexico, OTOH, is very nice and the Mexicans are very gracious and accommodating. Either Mexican coast is also cheap whether you're on a cruise or you fly in.
On a budget and want something fun and also nice?
Mexico, whether you cruise or fly down.