I just fixed a corner repair similar like that, I had the body pulled just back into (Close) alignment, then added Gen-Right corner crusher panels.
As long as the frame is ok, the repair will be under 1000$.
There are two places you need to look at before you buy, one is the gap between the rear door and panel, this can be pulled some but there are several supports behind and under the rear cross member support that you need to make sure that they didn't tear there welds.
Second is the corner itself with corner basket/light accidents the tub some times can be pulled down right at the corner radius. A good body repair man can push this corner back up flush with the rest of the tub but there is a possibility of the rear panel separating from the rear quarter panel.
The estimate to just replace the corner radius panel was from 400$ to 600$.
I had mine "pulled" for only 150$. The gen right corner were 320$, and I had them painted the same color of my jeep for 300$.
The install took about 4 or so hours.
Here is a link showing them "
link"
This was the corner before we put the panel on.
Incidentally I ran the light basket into a rock, pushing it completely into the panel.