No offense, but this an idiotic statement. So what if the $240 one sells better? The point is you CAN buy a RX 480 for $199. No one has said that the 4GB would outsell the 8GB. But again, that's not the point. If the prices and performance are correct, is a current 8% gain and one fewer GB with no multi-gpu option worth $50 to a gamer on a budget?
To this gamer on a budget, it is not.
But again, people talk about the $199 option because it's available, no one is forcing anyone to spend 40 more dollars.