It really depdnds....
Myself, I don't buy much, but my DS10 does like to shop.
His budget use to be $50.00 a day, but after multiple trips, and so much stuff he barely looks at now, it's been cut to about $25.00 for every 2 days for him. I allow myself the same amount, but I normally come home with most of that.
I rarely buy gifts for others. This year, I have requests. So I will try to honor as many as I can. I will also get the pet sitter something on top of paying for her services (which is cheap anyway-since she's family and lives less than a mile from me).