Ruger has a long-standing relationship with Davidson's and Talo for making limited-release editions of their line of standard products. These distributors are skilled at the art of marketing items as being worth more than average due to their scarcity. But unless you just have to have one, I wouldn't recommend laying out extra money for them unless you are a true collector planning holding these things for decades to appreciate in value to a small subset of other collectors.
I personally think the standard stainless steel GP100 is about as perfect as the design can be, so why pay more for less?