I'm an engineer at Holset.
Take this piece of advice from a turbo engineer. Cheap Chinese turbos don't perform anywhere near as well as genuine branded ones, they are made of cheap materials that are riddled with defects and stress raisers, they are nowhere near as durable and when they let go! My god the damage they do!!
Think about it this way - turbos of this size run at up to 180,000 rpm- 3000 revs per second! That's a lot of energy and inertia. The blades are travelling at about 700 miles an hour about the same speed a a bullet. Would you take a M16 to your engine bay?
When the turbo lets go the blade fragments have to go somewhere and on cheap turbos the housings shatter. Branded ones contain the wheel burst. The blades destroy anything in their paths, there are plenty of oil lines, fuel lines, brake lines, other expensive pieces of engine that can be damaged as well as lots of flammable fluids.
It's really not worth the risks associated with a cheap turbo. They are cheap for lots of reasons.