Reliable is relative to tune and parts that you get. Price id say 4-5k if your doing the work yourself. I spent probably 4.5-5k for mine. Parts to spend the most money is turbo, clutch, tune, and probably wastegate. As long as you dont push your engine (zetec good for about 12psi) I dont see any problems with durability.
Anyone else got something to add/correct?