Howard: The real price on those rings at Brownell's is $49, but they're not dual dovetail, just standard turn-in, unless I'm reading something wrong.
In order to get the $49 price, open an account with Brownell's online, answering the question regarding being in a business that doesn't require an FFL in the affirmative. You'll then be able to view the "trade discount" prices and order your rings at that price.