Both DH's family and mine always buy for the kids until they graduate HS. We do a gift exchange for one person (do a name draw at Thanksgiving) on each side 25-50$ so, we are not really spending a ton of money.

But, DH and I spend (some would say) an extravagant amount on each other for X-Mas. We do not have any children ourselves and we do not buy any other gifts for holidays/special occasions including B-Days. We usually just go to dinner so, that is how I/we justify it.