UPP doesnt necessarily mean a higher price, just control over the price and its consistency across different sellers. They can set the price high or low without UPP by setting the source cost itself, and even with UPP, seller can often find 'smart' ways of working round them e.g. bundling.
A good test may be coming up for Samsung soon. Amazon had the Panasonic P60ST50 and Samsung PN60e6500 both at around $1900 making them direct competitors. But recently, the Panasonic has dropped to $1600, so we will see if Samsung responds with a reduction too.