I'm not saying they are 20x as good, i've never heard Q7's in my life. My comment was only this: Nobody buys something costing as much as a Q7, then decides to replace it with something costing as much as a Montis.
It would be like replacing a Ferrari with a prius. They both do a great job getting you where you need to go, and the prius actually does some things better: its more efficient and cheaper. But it's not a Ferrari. If you sell your Ferrari, it's usually not to buy a prius, it's to buy a newer/faster Ferrari
I agree that the law of diminishing returns is in play when you compare two items which are so far apart in price. But unlike $$ figures, you can't quantify "twice as good" or "20 times as good" with your ears.