There really is not a hard number that you can grasp. As you said, it will simply affect the number of buyers who will want to buy the home in the future. More important does it affect you? If you are not concerned with any safety issues or having to look at it every day, then that is half the battle. Personally it is not something I would put up with but that is just me. Housing is way to expensive to plunk down all that money and be that close to the power lines.
