We'll spend about $50-$60 on candy to pass out-- we always get several hundred kids coming by, and with Halloween on a Friday, it might be over 500 this year.
No costumes for us, and the kids usually just put something together from the stuff they own. This year there's a football game on Halloween so they probably won't even bother with that.
And I didn't buy or build any new props for my front yard Halloween display this year, so zero dollars on that.