I have seen ones like this on ebay for years.
Proto seems to have given it a nicer look but its not new.
the price seems to be around $15 US. http://www.ansgear.com/Proto_Primo_Loader_Hopper_Black_p/protoprimoloaderblack.htm
check out the video on this hopper and see how it works, just like the one above but sleak looking:
http://www.youtube.com/watch?v=WupzwjkxsSY
