if you do it yourslef then none
don't buy from the states, we have plenty of locals whom import the buggers from Nippon. I'll track some down for you if you are trully interested. As to labour costs.... become frienldy with a mechanic and see what he can do. It's probably an easyish swap so if you are on good terms and manage to convinse him you know a tiny bit you might be ok with not getting ripped off.