[RWebb]

I agree with P O P partially (as usual). If the service is worth the 5% "skim" then fine. One potentially large benefit is that if a buyer asks about an issue (that need not be legally disclosed) and the seller says I don't know yet does, there could be big legal trouble. If a broker is there, they can just say truthfully they don't know. (does not apply to issues that are required to be disclosed by law).

If the service is worthless then I don't want to pay for it. I am finding that as I look at car dealerships - the sales people seem to know nothing and do nothing. So, why should I pay a big markup that they will get?

A tip in an eatery is based on service and I think most people will tip better for better service. That is voluntary. Sales of houses, cars, etc. have that built in and price negotiations should be based on the level of service.