Staffing prices vary around the country......
waitstaff-kitchen help, in the midwest would run approx $30-50 an hour, holiday would be double....
NOW, a caterer would make $15ish pp for 200 people +staffing to "make sandwiches".
Keep in mind its New Years Eve. Normally staff gets paid double if you can find staff. Figure yourself double to. Has this client used you before? and will they use you after NYE. I would get at least !7- 20 pp or it breaks to $340 t0 400.00 per hour.minimum and thats a good price. Remember TIME IS MONEY