[turbo2.0]

How long will a turbo engine last? Good question. I think that all depends on how mch boost you run, the conditions that control how it runs, and how hard you run it. The stock motor is pretty much bullet proof no matter how hard you run it, mostly because it is built very conservatively.
A turbo motor that is set up correctly, with a conservative amount of boost (around 5 to 7 psi) should not be stressed any more than a carbureted, cammed motor that is driven hard. The more power it makes, and the more often it is asked to do it, the more wear it will see.
I am in the process of rounding up an old engine, and an old set of heat exchangers, and will be picking up a spare transaxle in a few weeks. I plan to assemble these parts, turn the assembly upside down, and use it as a jig to start making turbo headers. That should be much easier than working under the car. It will take a while for R&D, but with any luck, I could start kicking them out by August.
Price should be about the same as an average aftermarket header system, with extra cost if I supply the turbo and other accessories. I can usually locate good used turbos for around $100, and other parts can be had affordably. Ultimately, the total cost will depend on how it is set up (carb vs. stock f.i vs. aftermarket f.i), how much boost is desired, and how much of the work you are willing do do yourself.
I know two people who are interested, and I will see how the demand is after that.