We do the same # of gifts. Typically, we try to spend similar amounts on all the kids but some years it is not possible. DD is getting a laptop as her big present this year and while I got it for a good deal at $299 + her other presents, there is no way we would spend that same amount on all the kids this year. DD needs a computer for school and since I'm pretty much on my laptop doing school work myself in the evenings she really can't borrow mine all the time. DS absolutely doesn't need that much spent on him, we probably spent $120 on him total. Yet SD's big present was $130.
We do same # of gifts because all our kids care about is that they aren't sitting back watching someone else open a bunch of presents when they only got a few. So that means, like in this year's case DD gets much cheaper other presents since her big present is so much.