I'm more likely to buy a gun on impulse than my husband is... and my ammo costs a lot more than his.
Of course in defense of my spending: I don't like jewelry, I don't own a purse, I have one pair of designer shoes I got at a huge discount for $22 in 2006, I do occasionally work a second job, and the last time I bought clothes was at the beginning of November and those were scrubs for work.
I just think open communication works. We both know what the bills are, we both know what the money coming in is, and we both know that our financial obligations come way before our hobbies.