I met a guy in El Paso that had one on his van. If your damages were 9K and 3 weeks off, it sounds like cheap insurance. The guy said just be sure to not tighten it down so much that there's no give to it. According to him, you WANT the give to absorb some of the impact. I have no idea how much one costs, though, or how to install one.
Deer terrify me, so if I owned my rig, I'd definitely have one.