Do you really save money at the commissary?

I'm curious, do you actually end up saving money when you shop at the commissary? It seems like prices might be lower than at other stores, but are there any hidden costs or fees that you need to consider? Additionally, do you find that the quality of the products is comparable to what you can find at other retailers? I'm interested in hearing your thoughts and experiences with shopping at the commissary and whether or not it truly is a cost-effective option.