That's not too unusual. The other day I was looking for a particular shoe at the Shoe Dept. at my mall, they didn't have it. They were short staffed and the clerk was somebody who usually worked at a store an hour and a half away and she looked to see if they had it at the store in her town where she usually worked because if it was she could bring one to me the next day.
As it was they didn't have it and we just ordered it from their online store.
Auto parts stores do the same thing. If you use Best Buy's web site they will tell you what is in stock at your local store and any other store, and they can pick it off the shelf for you and you can get it at the service desk.
I don't believe Costco always does this, but they have occasionally for me in the past year or so. I believe I've also been told that they can't do it.
