RS4
Skilled
Well there is definitively extra costs involved,but not as much as the companies are charging.
But they have put a lot into R&D to get them where they are today, in 2007 the Sony motionflow tech based on frame insertion used to achieve around 600lines of motion resolution with soap opera effect +input lag,in 2008 they achieved 1080lines of motion resolution by doubling the frames even more called 200hz motion flow but again with soap opera effect+input lag,now in 2011 they virtually eliminated soap opera effect.
Lg has been including "truemotion" backlight scanning for many years (even in low end models) much before sony or samsung,but lg still lags behind these two when it comes to motion performance.So over time these features will make its way to low end models.
The specs of Sony 40EX430 includes Motionflow XR 100Hz just like the more expensive 40EX650, check out the specs:
KDL-40EX650 : EX650 Series : BRAVIA? HD TV (LED & LCD) : Sony India
KLV-40EX430 : EX430 Series : BRAVIA? HD TV (LED & LCD) : Sony India