Your husband has needs and wants to, just like you do. Every once in a while, give him a break and avoid making a fuss if he wants to treat himself to something that may not be "practical," especially if he has been working extra hard to provide for the family.
Just try to keep him in check in case what he is eyeing is way beyond your budget, or is something that you foresee will become clutter in your home later on. Rather than telling him straight out that he cannot buy it, though, talk to him about why you feel it may not be worth spending on.