"You may send us your turbo for a free estimate. Upon receipt of you turbo, we will inspect it and give a free quote for repair. If all your turbo requires is bearings, seals, balancing, and cleaing, your price $275.00, plus freight. If your turbo requires extra parts, we will quote those additional parts as an adder. If you approve the quote, we will repair and return using your charge card or COD shipping. If you do not approve our quote, we will ship the unit back for the freight cost only. If you order a rebuilt turbo, you will be charged a core charge. The refund will be issued on this core charge, only after we receive and inspect your good, rebuildable core. You will be responsible for any damage repairs to your core."
From turbochargers.com. Sounds good to me.
A more costlier rebuild, is when you start to get signs of your turbo goin, ie. more smoke than usual, the typical "turbo whine" getting a tad louder, reduced boost, oil in places it shouldnt be, etc etc. and you keep runnin it anyways. I looked at mine, when the whine got a little 'whinier', and at that point, upon initial inspection, seen oil, where oil shouldnt be, so i checked shaft play/thrust, and wasnt satisfied it was as tight as it should be so i yanked it.... Not doing that, is when rebuilds start going up to 500 bucks or so....