You might find a database app helpful. I took a quick look at the 3 database apps that I have, Tap Forms HD, Bento, and FormsConnect, and at first glance, I think TapForms might be the best suited for the tasks.
There are number fields that can be formatted for currency. You could give each store a separate forms with multiple records, or you could just use one form and each store with its own records.
I'm sure the others could be used as well. A Bento template could be modified to meet your needs, but I have less experience with it.