Our insurance was around $4300 a year for a boat worth $180k. We are likely not going to keep full insurance for next year and have only liability insurance. This will be much less money. We do not have health insurance. We are Canadians and have some overseas coverage from this (depends on how long we are out of the country at any given time). Also, the cost of paying for any needed health costs are manageable anywhere but the US - we heard of people getting treatment for a major laceration in Grenada (3 visits to a clinic) with a total cost of $15 for the medication used.
With your budget you should do just fine. Someone suggested a catamaran. This would work well in the Caribbean but would be problematic anywhere where you needed to use docks. We have friends who have a St Francis 50 and it is remarkably palatial. They paid more than $1million for it but the construction quality was still a bit iffy. For something like this you are better off with a used boat that someone else has done all the prep work on.
A general comment I would make is that you should look for a better boat rather than a bigger boat. With your budget you should be able to get a large, high-quality boat though.
Finished the circumnavigation in early February in Grenada. Have to work on a book project for the next several months so the boat will be waiting for next year.