A “healthful” snack could be popcorn. Costco sells individual Skinny Pop bags 28 count for $14.50, about $0.50 per bag. https://www.costco.com/Skinny-Pop-Popcorn,-0.65-oz,-28-count.product.100381415.html
+1 Have given Costco popcorn on Halloween for a couple of years now. Kids seem, if anything, tickled by getting something different. (Last year a treater paused, looked me in the eye and said "Creative!")