Fifty cards - 10-20 on the cards, about 30 on postage - £50
Six niblings at 20 each - £120
Ten siblings and in-laws at 15-20 each - £180
Two parents at 20ish each (before my dad got dementia, anyway) - £40
Two children main presents at about 50 each - £100 (we have gone up to a few hundred occasionally but they were exceptional circumstances)
Two children things for stockings - oh lord, probably about another 50 each (included pyjamas, mugs, stationery etc) £100 [don't do this any more 
]
Each other probably around £100
Wrapping paper I buy cheap after Christmas, let's round up the total
So total on cards and presents £700
Food - goodness knows. Turkey used to be local farm Norfolk bronze at 50ish, rising to over 70 last time we did it. Last year I picked up a frozen one from Tesco, still free-range bronze, which on offer cost less than £16. Possibly not quite as much left over. Most wine and beer is the normal stuff we have which H makes from kits and works out at 50p a bottle; we have been known to buy dessert wine but last year had parsnip sherry which worked very well. Sparkling wine, gin and Bailey's more than usual: possibly £70 on alcohol. Maybe an extra 50 on general food? Difficult to say really: we have what we consider special meals but they're all just at the top end of what we usually eat.
Say £200 on food and drink, but that's being generous.
Travel - two tanks of petrol, £120
Last couple of years overnight stay in college room 60, chapel donation 20 - £80
Eating out (when it was allowed) - the four of us at home, once when visiting granny, maybe should count twice just me and H - say £150
Our Christmas entertainment is mostly free - we did do pantomime once but don't usually.
Grand total £1250
(though as previously noted that doesn't include the quirky musical instrument at £500 (S1) or the graphics card at £400 (S2) because Christmas was just the excuse for handover)