Our caterer owns his own business and we are paying him for food, service and rentals. Each workers (including him) costs us $150 and he divides it all up, so we tip him for the entire thing. The gratuity is at our discretion...but do I base the tip on...a.) just the food ($1,440)b.) food and service ($1732)c.) food, service and rentals ($1950)d.) food, service, rentals and tax ($2100)*e.) other*this makes the tip per guest 40% of the food cost.(The difference between a. and d. if $600 which is, ps., half the cost of my entire ensemble.)