We have a budget, but can usually come in under!
100 for my parents
50 each for DH's parents
40 each for his grandma's
40 for DH's ex-stem-mom
25 each for the 2 older nieces (they usually get gift cards)
20 each for all the other nieces & nephews
I usually spend all 100 on my parents since my 3 sisters and I go in together - we spend every last penny! But they do so much for us (babysitting, fixing things, etc) that they deserve it!
For everyone else we generally come in under budget!!

These numbers are my TOP dollar amounts!
Then there's my boys! I'm trying to keep it to 3 toys each from us, 1 toy from Santa plus stocking stuffers! That budget is ABOUT 75 per kid, but it's just an estimate! I try to get them things I think they'll enjoy but get them as cheap as I can! For my youngest ds I probably only spent 40 for everything! For my older 2, they probably got around 75!
DH and I just get stockings generally! Mostly deodorants, toothbrushes, etc so I don't really care how much I spend there - it's all money I'd be spending anyway!!