I only set a budget because I want to keep things as even as possible. I wouldn't buy for the sake of it but I do try to keep spending roughly the same and present number roughly the same. So I work out how much I'll have for Christmas. Take off food, family gifts, joint present, then divide what's left by 4. If one has slightly less and the other slightly more I'm ok with that, and if 1 has 1or 2 gifts more than the others that's fine too. But ds3 is so easy to buy for that if I just bought things as and when I saw them I'd spend 900 on him and 100 on each of the others. I think they'd notice that difference lol