I've been wanting to do this for years, but it's hardly "extremely affordable" – on average, it's anywhere from $3,000 to $10,000 per person for a 2-4 week trip.
Cruises can be waaay cheaper than that. Six adults from my family recently went on a 9 day cruise that was really nice to the Bahamas, I think the whole thing was under $4000.
Or one of those Caribbean leisure cruises? Those are cheap upfront - to get you in the door - relying on in-ship purchases (like alcohol & restaurants) to make the majority of their money.
