I used to do this all the time at two of my local grocery stores. Literally hundreds of times. I probably have saved at least a couple thousand dollars doing this. Out of the hundreds of times I did it I got caught about 5 times. Most of the times they just intervened and voided the item and rang it up as the correct one, a couple of times I got someone who freaked out at me (obviously embarrassing). But I didn't really care because it's not something you can get arrested for, when they intervene you obviously end up paying the correct price so you haven't stolen anything. And in any case it could be hard to prove intention because you can blame it on human error anyways. Recently I've been going to a different store though where there's a lady who watches like a hawk and has been catching me every time so that blew it for me, on to another store. But most of the time it stuns me how easy it is and how no one else seems to be taking advantage of this. Anyone else out there? Share your stories if so!