I know it's hard to generalize, but I'm looking at a tankless WH installation, one of the smaller units such as a Rinnai 2020W, Nortiz 63S or Taguchi Jr. My bathroom is completely gutted and the 3/4" hot/cold run right to the outside wall on which the unit will mount. Need 30' of 3/4" gas line run in the attic (cut into an existing line). What's a reasonable range for this sort of job?