The answer to your question, “just because we could afford to spend more, should I have to?” is absolutely not!
Your DH’s attitude is proof (if any were needed) of the consequences of overindulging children to the point they become ungrateful, self-centred, inconsiderate, rude adults!
When out 3 children were growing up, our family tradition was for them to have two or three presents each under the Christmas tree from us (plus anything sent by relatives) and a stocking from Santa. Santa’s gifts always included an orange and some walnuts in the toe, a new toothbrush, toothpaste, flannel, bubble bath, a book, a fancy pair of socks, a game to play, a jigsaw puzzle, a colouring book with pencils, pens and other stationery, a winter hat/gloves/scarf, 2 or 3 small toys, a selection box of sweeties, a bag of chocolate coins and a small soft toy (that we left unwrapped) peeking out the top of their stocking. All three children were always thrilled with what they got. Now our two sons have their own children, they do something very similar for them, which suggests they still appreciate their own Christmas traditions.
Young children have no concept of the monetary value of gifts, nor do they distinguish between what adults consider ‘utilitarian’ and luxury goods. They are simply thrilled to be opening the wrapping paper and building little family traditions that will give them a lifetime of special memories.
Without wanting to sound smug (as I certainly made many mistakes as a parent and there are loads of things that in retrospect I wish I’d done better as a mum) I think we got the balance right at Christmas because all three of our children turned into exceptionally kind and considerate adults who continue to express genuine appreciation for any small treats and pleasures they are given.
Conversely, some of their friends who were regularly given much more as children, have become unhappy, selfish, inconsiderate and entitled adults who show very little appreciation for anything.
Keep going OP… your children will undoubtedly be thrilled and appreciate everything you’ve given them both now and as they get older.