We often see posts like this come up followed by the OP going ahead and posting about how good it is.
Then a bit later down the line and they post up again eating humble pie asking why its not making boost, why is the power low, why does it smoke or why its heatsoaking etc.
A new turbo is about £1k incl labour. Blow your engine and second hand ones without the ancils are about £1.5k not incl labour. If you have issues consider how much fault finding is going to cost you!!
Im not saying to use the expensive top end tuners like APR, or REVO etc if you cant afford it, but there are plenty of options that are top quality, give equivalent figures and cost alot less . Such as PDT, RTEc, P-Torque etc. YOu have a lovely and expensive car, why would you scrimp on quality on what is basically the most important and critical part of the car.