My husband and I have two kids. My brother has two boys, different moms. Their moms always make sure they get to spend Christmas with us, so we spend $20-30 on each of them and I usually buy a nice little $10 something for their moms. The boys each give my kids $5 gifts and everyone is happy with that. My brother is seldom around, so we do not buy for him and do not ever expect him to buy for anyone.
My DH side of the family is a little different. We have two, one of his brothers has three kids, and the other has no kids. On that side of the family we all buy for my MIL & FIL, and the kids. We spend $20-30 on the niece and 2 nephews, and SIL (their mom) spends about that on each of our kids. My one BIL that doesn't have kids buys for all the kids, and spends a little more $40-50. That was his own decision. I think it is because he doesn't have kids of his own to buy for (has a steady GF now though, so maybe in a few more years :)) MIL & FIL buy for everyone, but DH, his brothers, and us wives do not exchange gifts with each other. The BIL that does not have kids kind of switched it up last year though and bought all of us adults a gift. He said that he wanted to get us a gift, and he would do whatever he wanted with his money and he did not expect us to get him anything. I appreciated the gift, but felt uncomfortable because we did not get him anything. Now I am wondering about this year - should I buy him something since he bought for us last year? Should I discuss it with him before the holiday? Or should I just do things like we always have and maybe stick a gift card back just in case he springs a gift on us, that way we will be ready?