I like coming here to do grocery shopping once a week, it's pretty cheap as far as a lot of brand items go compared to other grocery stores and walmart, and it let's me get gas and do a bunch of things on base. I've been going to the Commissary since I was a little child and has been usually the main source of groceries for my family for many many years now.
I do however recommend keeping look outs for sales out in town though, when that happens, it turns out to be a lot cheaper shopping their than the Commissary for that purpose.
There is a 5% surcharge on all grocery, including food and non-food items. I know out in town you don't get charged taxes on food items, but non-food you do. So really you need to watch out for the prices of things. I shop everywhere, but when it comes to Pet food, non-food items, and produce I generally shop at the Commissary because it's a LOT cheaper.