We do a Secret Santa between the siblings in our house (6 of all, all grown adults). "A decent present" is the instruction - roughly ?50 budget but I think some blow that one.
The other 4 (or even 5 if trying to keep SS a secret), as well as 3 significant others (which may even be 5 SO's this year, am not sure) all get a token, ?5 limit. We have a stocking each to put these items into (eldest sister was daft enough to sew these a couple of years back, and I am dreading being told that another 2 are needed this year as I've no time to sew at the mo).
I tend to spend about ?100 on Mum and Dad, combined. Some years a combined present, others are individual.
PIL get the same budget.
BIL and wife, I budget ?40 (I think this year will be less as we found something lovely in a sale), SIL a bit more as she's finishing a house and needs furnishings (maybe ?60).
I have 1 aunt and family on Mum's side to buy for, about ?30 for a family gift there. We don't exchange with my Uncle, and my Gran died during the year.
And my Dad's family is large but agreed last year to only buy for their godchild (and us for our godparents), with a KK draw for the siblings and husbands/wives (copying us!!). So we only have to buy for 1 aunt/uncle (I have my other Gran, in lieu of Grandad), about ?40 there too.
And then there are 3 cousins who are young (11, 7 and 3), as well as 5 nieces and nephews - about ?20 each on those.
DH has 1 uncle and 1 aunt, about another ?30 each. And another aunt locally here for a token, ?15 or so.
So there's enough (and then there's school teachers, creche minders, car drivers, au pair......and the postman's "box" - it all adds up here!).
I don't always spend the full budget, but I start out with a figure of close to ?1,800 in January and keep a close eye on sales, and get crafty and creative where I can too!!