Depending on the menu and service provided, it is subject to change. It is negotiable, I do many styles of events anything from casual "drop-off' catering to fine dining private dinners. High-end dinners are generally around 100 dollars a person. For two people you are looking at a minimum of 350. They are generally 4-6 courses made to your specifications. Dinners for 3 - 6 run for $120 a person taxes and travel included.
Be polite and understand. Do everything you can to meet their needs. Go above and beyond if need be. Keep the client happy.
I have an associate's in culinary arts, and almost 20 years in mostly fine dining restaurants. I have serve safe and HAACP food handling certifications. Have won many awards and accolades for my professionalism and plates.