Yes, in the greater scheme of things, the Off-road package seems remarkably under-priced for what you get - better approach angle, sump guard, uprated underbody panelling, extra drive modes and a 6 degree wider headlight beam spread. I like the 5-spoke 18-inchers because you can get your hand through the spokes with a wash mitt to clean the wheel wells. If you are keeping the car for a long time I would apply a semi-permanent glass coating to the rims. The hot particles from the brake pads can land on the wheels and burn through the lacquer. Then the road salt in winter gets to the raw aluminium and corrosion starts under the lacquer. I used CarPro DLUX, it is also great for protecting the exterior trim from the UV which makes it go grey and powdery over time.
Click here for DLUX info
Mercedes do seem prone to production delays due to stock control problems. Recently there was a long wait for cars with the black ash interior because it is only produced by one Japanese company who simply could not keep up with demand. Designo Hyacinth Red was my delay, they stockpile the orders until there is sufficient volume that it becomes worth putting it in the paint robots' guns. Buy hey, all good things come to those who wait.
You may want to check with your Stealer about the implications of fitting a towbar. I think it may have an adverse effect on the rear parking sensors. I know you can't have the hands-free tailgate operation but then that is only available with the Premium Plus option anyway.