 I bought a 2014 GL 550 w/ 40K miles in 2017 for $55K (original MSRP $95K in 2014 -- sharp depreciation!).  Had been part of MB's certified vehicle offering.  What a spectacular vehicle for the money!  This big MB is so fast, and handles so incredibly well that I find Texas's top, 80-mph speed limit to be frustratingly low.  Although intended for the US market, this twin-turbo V8 with wide, performance tires would be more at home at much higher speeds on Germany's autobahns.  The brakes are every bit as impressive as the engine.  In addition to almost preternatural performance for such a big vehicle, the interior comforts are also great, starting with the Harmon Kardon stereo, but also the massaging, heated & cooled seats, and triple sunroof.  I'm not a fan of the cumbersome navigation system, however, and children over twelve are uncomfortable in the third-row seats.  Finally, the MB dealer here in San Antonio has been delightful to deal with for routine maintenance.