Oh, you're the seller. Should have paid closer attention to your first post. It did mention sale
and not purchase
If you're a FL resident you probably know the state is picky about the sales tax and that some of the issues are not clear or not clearly understood even by businesses. I was a broker but it was over 30 years ago but I don't recall charging
sales tax on our commission. Last time I dealt with sales I worked at a computer shop. There we had to charge sales tax if there were any parts
or goods involved in a repair or installation
but if labor only we did not. This was also a few years ago and the rules might have changed.
I also called my father-in-law who is a real estate broker and sales tax is certainly not charged on commissions there but then a home sale is not subject to sales tax where a boat is.
I am guessing here but if the buyer is keeping the boat in FL he or she will have to pay FL sales tax on the total value of the purchase price
so they will be paying sales tax on the commission. If the broker is also charging
you it sounds like a double tax. I think I would question this charge or at least get a second opinion from another broker.