Am I surprised by this? Actually, I'm far more surprised by nVidia somehow gaining the capability to manufacture its own boards, than I am by the price. (I mean, 66% more than on NewEgg? This is Best Buy, after all)
My guess is that nVidia has these boards actually produced by someone else, (likely eVGA or PNY, both of which, IIRC, have produced their "reference boards" in the past) and simply re-badged it as their own work. After all, re-branding is a skill that nVidia's had years to hone!