$1500-2000? This is ridiculous. And likely only brought to market in Europe due to a dearth of A/C (or much need, for that matter).
The battery draw is extreme, which means you're running your vehicle. And in America that means if you are running your vehicle, you turn your vehicle A/C on. So what then is the point of this rig? Other than putting it in a tent or camper with no/low insulation?
A 5000btu / room AC A/C is <$120. They consume on the order of 550 watts / 5 Amps at 110VAC. 12VDC, ~46A, even higher power consumption, worse efficiency, but on the same order of power requirement. Either way you are running a vehicle with a higher capacity electrical system, more batteries, or a medium generator.
Main difference is you get a $100 1000watt DC inverter to run the wall unit. So for <$250 you get the same cooling capacity, about the same cubic and weight and power costs. vs this $2000 system. The price differential is almost as ridiculous as the idea of using a house / window A/C. How anybody can call $1500-2000 a reasonable price for a niche product is beyond me.
There are plenty of roofmount 12V Air Conditioners, thanks to the huge RV market in America. 2-3x the capacity at half the price of this import unit.
http://www.campingworld.com/search/index.cfm?catname=air-conditioners&type=c&ID=114