If 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.
The route has to be chosen, approved and surveyed by the proper authorities. Then a trench needs to be dug along its length so the piping can be laid. Once the pipe, valves and intersections have been installed, the trench is refilled.
With regard to cost, the materials themselves are not especially expensive. The recent development of flexible plastic and corrugated stainless steel tubing as a replacement for black pipe has driven prices down and also made repairs easier. The problem is that natural gas is flammable, and thus, dangerous. A botched or poorly done installation can result in a gas leak, which can easily lead to a deadly explosion.
As such, most states and localities have strict regulations on how lines are to be installed. That's not to say that it's impossible to do yourself, but unless you're very experienced, it's really not a good idea. A qualified plumber or contractor can install the line safely and according to the rules, so you don't have to deal with municipal fines and don't risk your safety and that of everyone who comes to your home.
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. Plus, you'll sleep soundly knowing that you and your family are safe.