I am so happy I have a local pet store that carries what Nelo needs. I don't go to Petsmart much except to get shampoo for the pups or perches for the birds. I don't buy food from them, tried it and none worked for Nelo.
It's always nice to frequent local stores. Global pet foods are local in the Toronto area and you can return rejected dog foods there in the original packaging, if more than 3/4 bag is left. Petsmart and Petco in US also take returns, so it doesn't have to be Chewys. Not sure about local pet shops that carry high end dog foods in US.
I too have 3 great local shops I REALLY like... So I'm not lost or anything, but I did like their prices and would check them b4 purchasing elsewhere. 2 of my places are within a dollar of chewies, so I'm good...