I suppose a 2012 S would be better but a 2011 should be fine. I went with an 2011 S since the dealer I was working with didn't have a 2012 S I liked and the 2013s were still $90K at the time.
You could try to find out if the 2011 has the upgraded shifter cables that the 2012 has. Some upgrades didn't wait until the 2012 model year. The biggest thing I don't like with the 2011 is the pedals which look like slabs of aluminum vs. what you'd expect to find in a regular car. I do prefer the 2011s aluminum dash trims vs. the 2012+ black ones.
As for pricing, I know Newport Beach (now call Orange County, CA Lotus) had a left over 2011 S in Persian Blue going for $69,900. But, I don't see it listed any more. I've seen some dealers (like the former Scottsdale Lotus) offer a 2013 IPS S for $76,000. So, that may help establish some ball park figures.