Valentine's Day is not a child's holiday. It's a romantic adult's holiday. The most I've ever done is let them exchange Valentines with their classes and sometimes I'd get them a $1.99 stuffed animal or $0.99 candy. This year, we did the class Valentines and made brownie bites to bring to their classrooms. My eldest is in middle school now so they didn't do Valentines at all, but had the option of buying carnations to give to friends. She still brought brownie bites to share with her first period class and they were a hit. :-)
We had plenty of brownie bites left for the girls to keep some home. I have two mini-muffin tins with 12 cups in them each. I bought a $1.99 package of valentine-style paper liners to fit and made 2 batches worth of homemade brownies and that was enough to make 8 pans of mini- brownies. All of the girls brought 25 of them to school.
That's all way more than I typically do for them. I only did it because my first grader's teacher requested that parents send in treats for a Valentine Friend Party. ::sigh::