Well, I hope you do get a few bucks back, but I think Wal-Mart will only do so if they have marked the item down at that particular store. Their managers seem to have more individual say-so on their individual store markdowns than Target or TRU does.
I remember a while back a Wal-Mart in my area had marked all their SAGA2 figures down to $3.00 - I bought a few figures, then went to a different Wal-Mart hoping they'd price match the other store, but they said that sort of thing is done on a store-by-store basis. Which made sense, as it was an individual store lowering their prices.
It's just like their clearance sections, you never know what you'll find on clearance there or what the markdown will be at each store.