Think of "some of those" turbos as a pile of parts in the corner that someone cleans up and starts trying to fit pieces together till it turns freely,then come up with some stamp that will impress someone like SuperKY,MegaDouble D's,Dominator... then throw it in a box,ship it overseas to you.......
Friend of mine got an ebay turbo that had a 24mm waste gate hole with a 33mm flapper lol