Amazon Prime Day is offering up a brand-new 4K TV, giving all of those big-ticket TV deals on Black Friday and Cyber Monday a run for their money.The best deal we’ve seen so far on a new big screen is this Element 55-inch 4K UHD TV, which usually sells for $649 but is on sale today for $399.Element 55-inch 4K UHD Amazon Fire TV - now $399 (was $649)While...