Explain to them that you don't have much money, but Christmas isn't supposed to be about getting presents and stuff anyway..
Then you think of other things to do.
I told my kids the truth about the whole pagan mess. We didn't celebrate Christmas.
I grew up poor.
We appreciated everything we got, even if it was one single gift. There were many Christmases when we got one gift each because that's all Mom could afford, and there were at least two Christmases when Mom just couldn't afford anything, so she turned our names in to a charity organization that delivers presents to poor children. We were grateful regardless.
I do what I can for my kids
epic doesn't have to be lots of presents - christmas should be about spending time together, not how much money you dropped on it