Another DH here. I get annoyed with what I see as constant acquisition of more crap. We started with an under decorated house when we moved from a small apartment, and DW started buying stuff. But then when we reached fully decorated, she kept buying stuff. Now we talk about her wanting a bigger house and she is still regularly bringing more stuff home. How many throw pillows can one house hold?!?
Like OP, she shops wisely and buys tasteful stuff on sale, so it's not so much a complaint about the money. It's more just that I don't understand or appreciate what seems to be an obsession with buying more stuff that we clearly don't need. I think she just likes the act of shopping and acquiring new stuff. It's not the stuff she craves, but the act of shopping for it. I suppose I do it too, but just on different things, and a lot less often. Maybe the trick is to shop at some place like Value Village, and make home decor shopping a one-for-one exchange -- for every new throw pillow we bring into the house, we need to exit one from the house.