Maybe that was $10 a day per person... Him, his wife, the baby and the BOAT.
Could be done if all went well and you pre planned and avoided some of the places that everyone wants to go. Problem is "something happens" more often than we usually wish...
When I'm on the hook I do save money as mooring typically are $20 to $30 per night in the "resort" areas of the Virgin Islands where I spend most of my time. As you can see from your local gas station, the cost of fuel is going up and except in some area in South America... they will continue to go up. I would not be surprised to see $8.00 a gallon for diesel in the next year in the Carib.
Personally, I'm addicted to ICE... gotta have that cool sundowner and a cold beer at some point in the afternoon is not often turned down. This takes power... as HUD indicated you have to have a large battery bank and a means of charging it. It you have solar panels and wind generator it will reduce your daily cost of running your engines but the initial cost is still very high.
As far as boat goes.... your use is dependent on what is recommended. Once your in the Carib the boat your talking about will be acceptable for some island hopping in good weather. It is not a bad weather boat. It is not a blue water boat... I know I know.. some have taken a canoe across the Atlantic.. but for real people, it is not something one would do with a small child and others you love.
From Miami to the Carib is not a easy day sail... get a copy of the Thorny Path for best information on what routs to select based on season of travel. Nothing is impossible... well almost nothing but reasonable limits and restrictions need to be considered.
Have you considered buying a boat in the Carib? Often far less expensive than in the states and already at the location you want to be. I would recommend you learn sailing first. No real point in getting a boat in the Carib if you have no idea how to handle a cruising boat.
I prefer a sailboat to a motorboat, and it is my belief that boat sailing is a finer, more difficult, and sturdier art than running a motor.... Jack London