Why is there a price difference here on Amazon?

I have the example of Call of Duty: Advanced Warfare here.

Why is it significantly more expensive on the PS4 than on the XBox One?

Above: PS4 version, Below: XBox version

Long live the free market economy… Every trader can set his prices as he likes…

Because apparently nobody wants to buy the version for Xbox One…

Supply and demand.

Because the demand for the PS4 version is higher.