I've having this done within the next month by a professional. I'm having a half bath put in my lower level (I have a bi-level) which does have concrete floors but luckily I have a crawl space underneath where they can get to the main stack easily enough. They are drilling a hole in the floor for the toilet and the sink I picked out doesn't have an overflow so should be easier to install. I was quoted $500 to $600 just for the piping which I thought was reasonable.