Costs will be whatever you decide....
Spending usually expands to income limits; but if one is frugal and been a "saver" all one's life??
I plant to retire to the boat. While S.S. isn't the 'be all-end all', it will be enuff to support me in a lifestyle I choose and am accustomed to. Living on the hook, cruising instead of dock-ing and living day-to-day as cheaply as possible leaves more disposable income to blow on fuel and maintenance! LOL
Best of luck!