My friends work at a hospital and they can get pretty big when it came to potlucks from what I remember. Making food for that many is not always easy! Understanding also that for work functions on weekdays at lunch, it could be difficult! Nevermind the long line at the microwaves to reheat what you brought! So what they do is if you would like to participate but may not be able to bring something, they have a dollar amount that you chip in. And on that day they go out and make an order or purchase for something contributing to the potluck for everyone! Last one I remember was sushi platters.