Wives can have expensive toys. You just have to show them who is the boss and it certainly isn't them.
I remember a few years ago hubby coming into my networked computer room and looking at everything I had in there and his starting to fuss about it all and how I did not need all of that and should get rid of most of it.
I gave him that kind of stare that he knew to back out of the room very quietly and go back to his toys.
I wrote up a list of things I would get rid of if he got rid of items he should get rid of. In his list was all the shotguns, rifles, fishing rods, fishing boat and more ....one for every item he wanted me to get rid of. I gave him the list and told him when he got rid of each item next to the item he wanted me to give up I'd get rid of mine.
He left me alone after that.
Just like he does not ask me permission to buy his toys I don't ask him permission to buy my toys.
You should not feel you have to justify what you want to buy and just do it.
ASK HIM when his boat is going to pay for itself! Bet that will shut him up.