The other vendors will come along eventually they have SP1/2 and Surface rt/2 supported. Mr First to market is getting away with highway robbery for now since it was the only thing available in the beginning.I was almost drooling until I looked at that price. I guess I will experiment and make my own one day.
This looks like the same unit Mikegyver is selling only much cheaper.
http://www.amazon.com/gp/product/B00PQUCE9O
Note: Surface Pro 3 cable is not included. Sold separately.
The stuff mikegyver was selling was utter daylight robbery, but he could justify it at the time because there was nothing else available on the market.
Maybe Mike gets some credit for providing product for what was then an undefined and uncertain market. Several of us here went through the learning curve on accessory power for the SP1 (the old posts are probably still back there somewhere), and Mike also provided technical help for our efforts, even though it wasn't his product.
Regards,
Russ