Pet food quantity - large package or small package?

Chinchilla food mostly comes in smaller packages. I think there are some brands, such as Mazuri, that are sold in larger quantities, such as a 25 pound bag. However, I bought that from a feed store several miles from home. It is also available online. The brands readily available in pet stores are usually about 2 to 5 pounds. When I owned several chinchillas the larger bag was more practical. However, now that I only have the one chinchilla, I buy the smaller bags both for convenience -- the pet shops are nearby -- and for the freshness of the food.