Model number confusion re 8500 and 9000 series
The UNxxB8500 models were backlit, and one of the only few we've ever made. Production - and retail - costs can be really high on those. And those were back in 2009.
Edge-Lit LED is very similar in that the picture quality is great, even though the dimming isn't localized as much as the back-lits, it can still be dimmed in areas, and this is significant.
That said, while the panel can still dim areas using Edge-Lit technology, it also allows for the thin designs you see today. Back-lit panels would be thicker.
All of the LEDs from Samsung in 2010 and 2011 are Edge-Lit. And while perception will ultimately dictate for each person, I think the Edge-lits are just as every bit as good as the back-lits.
Does that help?