Charging for shop rags?

Camping world rates are 119.00$ a hour. To install a washer and dryer it takes a minimum of 2 to 3 hours. Depending on if you have to cut a vent hole, sometimes connect water lines, redo cabinetry, etc. Its taken up to 6 hours on units that are not made for washers and dryers. So at 29.99$, lets say at a low end it take the tech 1.5 hours. Normally that would cost lets say, 180.00 for install. I would say you are getting a pretty fair price even with shop supplies, not just rags. and yes WD40 does cost money, along with clamps for vents, mods to water lines that never show up on the bill, etc. etc.