They are not a huge market for Electronic Dog Fences in this area.
The few that I have put in I charged 10 cents per foot.
I made a V shaped plow from an old wore out mower blade, two steele pusher wheels and two pieces of 1 1/2" piece of square tubing. It basically looks and works as a sulky when attached to the walk behind mower. It will plow an opening about 2 inches wide and 3 inches deep. Once the ditch is dug. Just drop in the wire and stamp the ground back together.
One of the easiest ways I have found to get cost of doing such a service without flat out asking. Is to have them come over and give me an estimate of what it would cost to do the job. Then I have a base price to go on when decision time comes as to weither I want to start offering the service myself.
Edit:
If they coustmer can wait or you wish to stock up on a couple of fences. Northern Tool has them for $99.99 + Shipping. I have installed two of them and they do just a good of job as the ones that come from Lowes that sales for $149.00 locally.
You can check them out below.
Electronic Dog Fence