I think I'd be calling my legislator. There should be an exception for gifts collected and disbursed by a non-profit third party. If the teacher does not know the source of the gift then it is impossible for it to result in preferential treatment for anyone.
What the state thinks doesn't matter in our case b/c it is a private school. No one knows how much money any one family gives, because it is all sent in as cash in envelopes to the school office or to a PTO officer's home, collected by the PTO, then split evenly among all the staff members except the Principal. We give about $100 each year, and we have one child (who has 8 teachers); I'm sure that there are some families who give nothing, and some that give quite a lot more. We are normally not told how much each staff member recieves, but last year I happened to find out because I knew someone on the committee; they each got $300. There are 43 staff members who are eligible, so we can infer that the total collected was equal to about $40/student.