I just did a search on Dassault Falcon airplanes. They have a nice website with service centers and airplanes for sale. We have always went back to the factory for most of our major maintenance. I'm sure the company would demo a plane for you or help in the buying processs. I don't understand the need for a broker when dealing with a company that made the airplane. Dassault Falcon has a good reputation and are not going to rip you off.
It depends on what you call getting ripped off. Dassault, like any other company, is going to make the most money that they can get on a transaction. The buyer's broker is there to get you the best deal as well as to protect you from things that are hidden in the paperwork. Doing a pre-buy inspection doesn't cover all of the things that can bite you. I have seen a deal that was done in good faith by both parties but problems were uncovered years down the road that a good broker would have been able to avoid. You are paying the broker for his knowledge and experience. Obviously you need to make sure that you get a broker with the knowledge and experience to be able to do the job for you.