Hello All:
I have been lucky enough to work at a Cessna Pilot Center/Service Station selling used Cessna planes as a broker, ferry pilot, parts manager, and warranty administrator for the last 2 years. Our brokerage fee 5% for aircraft under $100K and 4% for aircraft over $100K. There is also a $300.00 setup fee charged to the seller for scanning of the logs, pictures, and web posting. This charge assures that the seller is a serious seller if he is willing to sell the aircraft and not just wasting your time with an outrageous asking price.
I am a new member here (just this week) and hope this helps.