I'll be honest: $99 seemed inordintately exorbitant for a mounting plate; however, it was well worth the price. The plate is robust, thick, and well-made. I wound up painting it. Quite pleased with the results. If you've got a GX470, and you're sitting on the fence, I'd highly recommend making the investment.
As an aside, the Hayden cooler is about 3x larger than the factory cooler and sits above the bumper, which allows for insanely improved airflow. Even in stop-and-go traffic, my fluid doesn't get about 125° F.