Only the contractor can tell you exactly how much the installation of a natural gas line will cost; it's best to get several estimates before moving ahead. One plumber on FreeRepublic.com gave $15 to $25 per foot of line as an approximate figure.The good news is that natural gas is often cheaper than electricity for running appliances and better for the environment than oil, so you're likely to recoup whatever you pay for the line's installation before too long.f you're interested in saving money by switching to natural gas to heat your home and power your appliances, you may have to have a gas line installed to bring it to your door. If that line will run through public property, it's not a simple process.