In all of my life and all of the times that I've done a price match at WalMart, I've never been given a hard time. Each time I've ever done it, all I had to do was present them with an ad with the lower price being shown next to a picture of the item I want to buy.
They didn't have to call the other store.
The other store didn't have to have it in stock.
It didn't matter if it was a sales item or not.
The store with the lower price didn't have to be local.
I've printed ads off of the internet from salespapers from other STATES, of stores that we don't even have in this area anywhere close to me, and they didn't even question it for me.
I just did it today actually. I also recently did it for the TCM 2-disc DVD and the Master & Commander 2-disc DVD, all this month.