My buyers broker has gone way beyond helping us find and negotiate the boat price. Especially after the sale
... he has gone down and double checked the lines when I am not able to, he has checked the bilge
after major rain storms, found us cheaper prices on things we need, suggested alternatives to upgrades we have considered, found us a better place to haul out
He even offered for he and his son to come down and help my wife and I take down and stow the sails
... something we have only done on our old (much smaller) boat.
So, if you consider only the sale
price of the boat and its function on commissions AND you have been down the purchase
road before, you may not get much out of a buyers broker.
However, having someone light the way before us and provide after-sale support has been wonderful.