My venue does all the catering in-house. The actual venue rental is really cheap because they're getting most of their money from the food, which means the catering fee has a lot of additional things built into it (day-of coordinator, cake, hotel rooms, etc.). This also means that the catering fee is really expensive, because it's covering a lot more than just the food, but there's no actual breakdown for me to see what percentage of the fee goes to the food versus other things.
So... how much do I tip the catering staff? If I do a standard 20% gratuity, I'll be adding almost $2k just in tips, which seems like an awful lot of money considering we're doing a buffet and not even a seated, served dinner. I don't want to be rude, but I don't want to tank my budget.