Just taking a quick look at classifieds ads shows a 2010 CL65 AMG going for $89k. This is not a car that holds its value. Does anything make it special? Well, for the 2013 model year it gets the new 6.0 liter M279 V12 Twin Turbo motor which is really a slightly refreshed M275 V12 which was already available. This updated V12 also goes in the new SL65 AMG. It gets a new engine management system, revised cylinder heads, revised turbos, revised exhaust system, and a revised ignition system.
Nice car but buy it if you simply have money to burn and are oblivious to the market. Or have no idea that a CL63 AMG exists with the more advanced M157 5.5 liter V8 that can put out more power than this car simply with an ECU tune while carrying less weight.