First, costumes (even sheets for ghosts and make-up for beards) can be beyond the financial possibilities for kids and teenagers. Penalizing these kids for the fact that they can't afford a costume just seems incredibly wrong.
If you want to read an anecdote about how I feel read on (and I won't hold it against you if you don't).
When I went to college, CPS (the office that you could go to for volunteer information) had a trick-or-treat night for the children of the migrant workers in the town where they went to freshman dorms. Maybe one or two of the kids had costumes and more than a few were grabby. Some of the parents wanted candy too. A few years later when I had a position with CPS, I discovered that a lot of freshman students had complained because of the lack of costumes, the grasping kids, and the parents who wanted a piece of candy. I was really upset by the fact that students had complained. These kids and parents were living paycheck to paycheck. If a medical emergency happens, they have to pay for it. They aren't getting a lot of money for doing agricultural work (apples in this particular area). These kids may not get candy all that frequently. Plus even kids who do get candy more frequently can be grabby. As for the parents, why begrudge them a piece of candy? They're just as likely to not have candy as their children (perhaps even more so, since they might get some candy for their kids and none for themselves).
