Audi aren't ever far behind them tbh. If VW made the same car, the options cost would be around half.
That is what I liked when I spec'd my last Merc, I just added the Premium Plus to my want list and it was~£3k +VAT at the time, but added absolutely loads of kit, Burmeister sound, Panoramic Roof, larger infotainment screen, COMAND Online system, and a few other options, something to do with memory seats, and mirrors or doors or something that i clearly wasn't too fussed about. I know the GT is a premium vehicle, but when you are buying at that end of the market are you happy to just get the pee taken out of you, I guess you just bend over and take it if you 'need' carbon inserts.