How much spending money is reasonable?

Edit: Thank you for all the responses, the compassionate ones as well as the tough love. Lots to consider going forward, breaking generational trauma is not easy but I haven't given up on my husband yet. A good heart-to-heart is certainly in order.

Original post: For context, we make about $1,700 a week, married with 2 kids in daycare. My husband smokes and drinks which is obviously very expensive these days. We generally budget $300 a week for him, but lately it's been more like 400 - 500. A pouch of tobacco alone is about 190. Yes I see exactly where the money is going, no he doesn't gamble or anything like that.

I'm tired of constantly nagging about money, but the man just can't stick to a budget. He'll blow through his 300 bucks and then just keep putting stuff on our credit card. We're not struggling to make ends meet, but it just kills me to see how much money we're wasting on this stuff.

So please tell me, how much spending money is actually reasonable for a smoker and drinker?