Turbo plus other supporting mods such as clutch and etc... Not cheap. The general rule of thumb for street turbo setup is cost of turbo times 2 for the supporting mods and tune.
Don't get stuck on the numbers of "350". The video below is probably around 270whp on a Mustang dyno (likely 300 on Dynopack). Judge for yourself if this is around the power you want. I personally don't want anymore power than this for the longevity of my motor. I drive most often running far less boost, only adding more boost and better fuel for the race track.