Not including gifts. I'm thinking of the special food, drink etc.
I generally host between 12 and 20 on Christmas day so have economies of scale but do go all out so probably £15 per head approx plus any wine/beer which guests may bring. Includes a nice brunch, big traditional meal mid afternoon, crackers, nibbles at dinner time, (inexpensive) wine for the table etc.
I don't buy a fresh turkey from the butcher or it would be a bit more.