Aren't we all? The other day I received a $10 off a $50 purchase coupon from WinCo. Sweet! We all get coupons from time to time from WinCo, Safeway, Fred Meyer, etc. Since it's money that you weren't anticipating, why not put it toward a few items for your disaster supply kit.
I already needed groceries that would far exceed $50 at WinCo, so I used my extra $10 for AA batteries ($7.99 and a gallon of water $.99). The water has a shelf life of one year and the batteries claim they will be good until March of 2017, so for no additional money out of my pocket, I added two useful items to my disaster kit.
Did I want to use my "free" $10 for disaster supplies? Not really. I would have rather bought $10 worth of buttered popcorn flavor Jelly Bellies from the bulk food section. But, alas, I wanted to be a role model of fiscal prudence and bought the disaster supplies instead. They won't rot my teeth or gross out my family like the aforementioned Jelly Bellies.