Okay .. if Audi only helps it is typically not going to be above 50-60 percent. If that proves to be
 

the case, I would suggest you look into purchasing a used turbo and DIY. It isn't a difficult install .. the engine brace is a pita and getting to one of the coolant lines is a bit of a pain but other than that it is pretty simple. That way you ought to be well under the half AoA would leave you with. Good learning experience as well.

Replace myself??
 

Is the turbo somehting I can replace myself? Or do I need a professional?

Not very complex an install if you are reasonably capable.
 

It would save you a ton of $$$ if you DIY.