C.O.
It depends upon where it is and if it's already plumbed for one...like a basement...
If you do a lot of the labor yourself - you can do it for about $1,000...however, if you need a contractor to do the plumbing for you - thousands...
Go to Angie's List and search for a good plumber and contractor in your area. get at least THREE quotes and ensure that you do reference checks and can see their work.