If you order from someone close to you, it will be cheaper with shipping than actually getting it from a store. The stores usually have the "culls" that people sell them. For example, whenever I cull my shrimp I bring them to the local pet stores in my area. I get more for my grade A CRS/CBS than I get for my grade SS that I sell online. I refuse to sell my higher grades to a pet store since they do not use RO water which means they will be dead in no time. You can find sellers that charge 10 bucks for shipping on here so it's really not that high of a cost.
In my opinion you should start with a decent grade of shrimp anyway. It almost makes no sense to keep the lowest grades of anything since the parameters and care is usually the same as mid grades.