You are paying for NDAA compliance...
Now that particular camera does have a varifocal up to 143mm, which beats most other fixed cams. The 5241-Z12E maxes out at 64mm.
So to get that kind of optical length, one would have to usually go to a PTZ, which is a lot larger than this camera.
But you are also paying for a 1-800 support line and the overhead that goes with that that the Dahua and Hikvision don't offer (unless you go thru an authorized dealer/installer).