I thought this whole thing was supposed to be simple
Clear as mud...
Lou45's reply is pretty cut and dry, but for some reason many gun shops don't even know what's going on.
I know the places that I have dealt with, do all agree that you only need to have one "with you" for pickup from their store.
If you own, or borrow one, that's all you need to do is have it with you. You don't to buy a new one for every gun purchase.