that is too true, we also buy a ton of stuff and if you saw our house you would think you were in PV.
It is tricky giving things out without being insulting to the parents and the kids that are selling won't take anything from you, they are there to sell. We usually try and give a few things if we are on the beach and the lady who braides hair is there with her child or the sellers have their kids with them. It is more of a personal gesture than just randomly handing things out. What we love to do is take things to trade, that really makes it fun. I get stuff I want and they get things they don't normally have in their stores or can't afford. Brownie mixes are a huge hit.
A few years a go my kind hearted Mother took dog biscuits because she was so sad for all the homeless dogs.