Get them to check the back room dude. Because they could be sitting back there waiting to be shelved -- and Toys R Us staff are like newborn babies... if they can't see it in front of their faces, it doesn't exist! Peek-a-boo! There's a toy!
Well, it's up to you if you wanna wait for a sale. With 'hot' toys like MP10, I personally wasn't willing to risk it.