Turbo should last several hundred thousand miles. The only thing I can think of is do you just shut it down after a hard pull? If you don't let the turbo cool down for a few minutes after its been working very hard, the oil in it will coke and eventually it will plug the oil passage enough that it may start to starve it for oil. An EGT gauge is good for knowing when to shut it off - preferably below 300 degrees.
Otherwise it may have just been a latent failure.
BTW, $2200 at a dealer isn't a bad price at all. You could probably get it done cheaper at an independent shop though.