The line under the house may have roots in it, but they are growing back from the section outside the house. Running a "small cutter" through a line is completely worthless. You have to run a BIG cutter through it to remove a many roots as possible. I also recommend snaking periodically, until it reaches the point where the stoppage is occurringat less than one year intervals. HOWEVER, from you description, a new line could be installed very easily and usually for a lot less than the costyou were quoted. WHERE 100 miles East of Chicago?