She needs a hobby other than spending.
This was my thought, too. Does she have a job? How much free time does she have?
Listen...I'm guilty of the same trap as your wife. Maybe not to the same extent. I've never spent $1000 in a month. But I am a sucker for "sales" and "bargains". YES my logical mind knows that whatever the sale price is, it's cheaper if I just don't buy it AT ALL.
I fall for the devil on my shoulder that says - you'll never see that deal again!, and it's no big deal it's only $20, and my personal favorite delusion - my husband will be so happy I found these things so cheap! I just saved us all of this money! Haha, no.
Here's how I combat it -
1. I am so busy I really have almost no time to shop. Maybe once or twice a month. That means I can't be out there every day looking at things that I don't need. I work full time, and I've filled up my free time with getting involved in my kids activities, and volunteering for the local animal shelter.
2. I have a good job that pays a little more than my H. Point being, I pull my weight in bringing in the money to pay for things.
3. We do what another poster said - we have 100% joint accounts, but we have only ONE of the accounts that is tied to a debit card and that cash can be pulled from at the ATM. The other two are for bill paying (bills automatically debit from it) and savings. Our financial departments at each company allowed us to each assign a specific amount of our checks that gets automatically deposited into each of those accounts. We pretend that all money outside of the spending account does not exist.
4. We do have credit cards, but they stay in the safe in the house and do not go out with us. We keep them for emergencies and for when we feel the use of them is beneficial. (I've got some that have 0% interest for certain things for example).
Honestly I couldn't stand my husband policing my every expenditure either. I do not think I am completely outrageous in my spending BUT I am definitely looser than my husband is by a significant margin. He is the man who could spend $60 a month on groceries (canned goods, cereal, milk, peanut butter and bread is what he lived off of) and he really could not fathom that other people spent more than that. We have made a deal that the joint spending account is "free money" for both of us. He doesn't say anything anymore. It does help that I am spending maybe $200 a month on stuff. With our salary that is doable.
Could you set something like that up?