I'd been considering a 4 series TV at Target for $449 last week, but missed it by going camping. However was at Costco today and saw this 5 series for even less. I can't find it on their website, and I failed to take a picture of the tag and display while at the store, but here's a pic of my receipt.
Looks like this is a clearance deal at B&M only, so here's your obligatory YMMV statement.
I got the last one in my store in Issaquah WA (unless they'll sell the display?)