I easily spent $700 for the twins for 7 months of Kindergarten. The school supply lists were nuts. We had to buy Crayola brand everything plus baby wipes, clorox wipes, dry erase markers, Kleenex, printer paper, etc, all name brands required. They constantly needed things for "special" projects. My kids have several nice outfits now but when they went to PS I had to buy outfits to be at school every day. I didn't send them in "play clothes" (at least what we term play clothes lol, no offense intended). I don't let my kids wear play clothes to the grocery store, or anywhere out of the house. I guess I was just raised that we should always look presentable out of the house because that is how people judge you, right or not. (I blame my parents lol.)
I didn't include gas costs either since I suppose it was my choice to drive them but in our rural area HS, MS and ES all ride the bus together. I didn't think it was great for my 5 year olds to spend 35 min on the bus with cussing 17 year olds.