GAW: NO one is creating a chiyuv mamon. That can only happen if it becomes a minhag which it clearly is not yet. However people need to ask themselves the question.
And the question should not be how do I show a token of appreciaton, but How do I compensate them for the service they have done for me and my child.
If the individual parent answers that an appropriate compensation is a card/flowers/box of chocolate. So be it. BUT ask the question.
I have never heard of these people(OOT?), Which people have you never heard of
Richards Lewenstein and Levy??
I’m not sure what country or circles you travel in. If you travel in the lakewood circles (as your last post indicated) and you haven’t heard of them then you must be on a different planet.