Got it for around $70 on Ebay. It works well as a reg. back up camera as well as an aid for hooking up a trailer. I previously had a cheap camera and monitor installed that worked ok but died. The Hopkins camera install is pretty straightforward but you will have to splice into your wiring for power & backup signal, which is no big deal.
I mounted the monitor to my dash in the far left corner. I'm not sure there is enough cable supplied to reach the rearview mirror, but I've read that Hopkins will send you a free extension cable if requested.