Installing an invisible dog fence can cost $300 or it can cost over $1,000. How much you end up spending will largely depend on the size enclosure that you're after. Most kits come with enough materials to cover at least 1/3 of an acre, although some can include an acre or two at a minimum.
If you choose to install it yourself instead of having a professional come out and do it for you, you're looking at a pretty penny. In many cases, this is over $1,000 just to have the wire run and the transmitter and collars set up properly. Fortunately, if you're able-bodied and have the equipment to do the job, you can do it all yourself without too much trouble. It just requires a long weekend of work.
This is true, of course, if you get an invisible dog fence that has wiring to it. If you get a wireless dog fence that operates off of a wireless signal and a radius, you can do it for just the cost of the kit itself. It doesn't take much effort to set up these wireless systems, but they do have their drawbacks. Doggy Bakery can tell you a little more about this.
First, they only operate off of a radius. You can adjust the signal radius up and down (usually around 90 feet maximum) with the push of a button. The problem with this is that if your transmitter is close to a roadway, you're pretty restricted on how far you can set the radius before your dog can get into the road.
If you have a home that's further away from the road than 90 feet, a wireless fence system may work out great for you. You just have to be careful around your driveway, because your pets can likely still get into it.