~ $300 for the turbo manifold
~ $800 for a new turbo
~ $150 hook up materials
~ intercooling will probably add about $ 600
maybe $ 400 on misc exhaust work.

an intake shouldnt cost much more to make, but then you need a throttlebody, air intake filter, etc...

figure $3-4k to do it right... cutting corners you can save money in the short term. unless you get free engines it's probably worth doing it as right as possible.