Whats the difference between the mitsubishi ws313 and ws315 models?

I've been looking around and I think I am leaning rather hard toward the 65 ws-313 however that is an older model and the 315 is replacing it. Is there any reason to pay the extra 300-400 dollars for the new model?

Also Bestbuy seems to have the best prices for these particular tvs in my area, is it that bad to go through them? Even seaching around the internet I can only find a few prices that are better then there ws 65313 price of $1999 and most of those are refurbished, and I'm not going to buy online anyways. Should I try to find a place to price match? Is best buy really that bad with things like this. I've never had a problem with them before but I also haven't bought anything very big from them either.


thanks
Ph