I am working class, so I spend a few hundred pounds per child 
I genuinely don't have a budget, and everything I buy will hopefully be used.
No clothes until they are teenagers, they find that boring.
No books, because they are treated as a necessity like food in here. I want all my kids to read, so they go to the library and we buy books all the time, they are not a treat. Other people spend a fortune on sky and other and find it a necessity too!
One big present - whatever is needed that year, could be a bike, a tree house, a computer for the eldest.
Some bits they have asked for: legos, playmobils, cars, barbies. Expensive but they last for year.
A few things they will like, I like the idea of surprise and some bits (jigsaw, games), stockings are full of chocolate. They must have around 10 presents each maybe? I prefer spending more on things that will be used, will last for years.
We also spend a fair amount on Grotto, Panto, Christmas parties, Christmas fairs, Things to do during the Christmas holidays.
I would never spend more than we can afford, it's all bought and paid for by the time we get paid in November, so we are not broke in January which makes the new year a lot more pleasant.