I've been using NIS since 2000 and I've never understood why a brand new purchase every year is cheaper than renewing.
This year I got a 30% discount via the symantec store and an additional 15% discount for being a US customer. I ended up getting a new 1yr NIS 2013 subscription for $42 whereas renewing my existing 1yr subscription would be $69.
I don't understand why there isn't any customer loyalty to promote renewals instead of new purchases. As it is, I mentioned in another thread that I can't even get my existing NIS product to accept the new 2013 key which makes the whole renewal process that much more frustrating.