the 50UT50 is $759, again, at Sears right now. For me, with sales tax (6% in MI), it ends up about the same as the $799 currently at Amazon. However, you can get an additional 4% rebate through fatwallet, by signing up for their cash back program and clicking through the Sears link on their site. I'm not affiliated with fatwallet, but have used the site for several years and it's definitely legitimate. It can take 60-90 days for the rebate cash to become available, but when it does, you simply request a payout through Paypal and you get the money.
I just bought the UT50 online for local pickup and received my cashback notification email in about 30 minutes. So, the deal for me is: $759 + 45 (tax) - 30 (cashback) = $774 total. About 10 days ago I bought the U54 at Sam's Club for $686 out the door, but it's now going back. Less than $100 for the upgrade to the UT50. I don't think this deal can be beat on this TV.
Oh, and like mentioned above, it looks like you can get an additional 10% using a Sears card. I don't have a Sears card, but for those that do, this is unbeatable.