This year, spouse and I have a $40 limit for each other. Kiddo's likely got that from us, too. I'm making shop aprons for 3 of my nephews (already have the fabric) and usually, with the nieces and nephews, there's a $20 limit per child. Adults usually do in-family Secret Santas ($25 limit).
It might sound stingy but we figure that A. the kids all have TONS of stuff and B. we don't want to go into debt over a holiday. I'm sure as Kiddo gets older we'll likely spend more, but we have a strong belief that Christmas is ONE day on the calendar and while it's special, it's not something one goes into debt for. If kids want the bigger items, they can help to save up for those.
(I grew up in a family where Santa brought socks and pencils and we had peanuts and oranges in our stockings-- a mini Whitman's sampler if we were lucky... how things have changed!)