There are lots of ways you can save money on your preps by reusing items. I clean and reuse 2 liter bottles to store water. I save any kind of sturdy, resealable bags (from dogs or cat treats, individual servings of freeze dried food, etc.) to use place smelling things in while my family and I have to say in the fallout shelter. These bags are great for dog, cat, or chicken poo. I also save old socks. I wear my socks until they have holes too big to be comfortable, then I wash them, and put them in a sterilized bag. Socks can be used to help stop bleeding from gunshot, knife, or other wounds that may bleed a lot. I usually buy my coffee in bags, but from time to time I buy it in a can. The metal cans can be used to store small electronics (to help shield them from an EMP) or screws, nails, pencils, and a number of other things. The plastic cans are great as pots for growing a small vegetable or herb. I have grown tomatoes, peppers, and carrots in these plastic cans (without the lid on). Some of the plastic cans I fill with potting soil, put the lid on, and store it. This way, I can start growing vegetables in the fallout shelter without having to wait for the soil out side to be radiation free before planting the seed.
I'm sure there are many other things around our homes that can be reused for preps. Before throwing something away, ask yourself, "Is there any way I can reuse this?"