dark area when shooting at 8000 shutter speed

[idbrew]

just bought the Mkiii Canon 5d as a back up for my other and there is a dark banding across the top of the screen. Ive been told this is to be expected, however I checked same settings with my other mkiii  camera and no banding. is this a failing shutter? 

[MikeSowsun]

Looks like an impending failure, or "shutter bounce", which tends to happen at high shutter speeds. 

[shadowsports]

Greetings,

Just how "used' is this body?

That looks like the shutter curtain.  

***Edit*  Mike beat me to it.

[idbrew]

is that a cheap and easy fix?

[MikeSowsun]

Shutter replacement is the only fix. It is neither cheap or easy. Plan on spending at least $300. Maybe more.