Each year, the cost of lightning strikes adds up to millions of dollars of damage to electrical systems in homes throughout the country. To prevent this from happening to you, install a surge arrestor. This investment is the initial step for whole-house protection because it safeguards hard-wired equipment like air-conditioning systems or appliances that can't be protected by plug-in surge devices. An electrician can install an arrestor for between $100 and $200, but it could save you thousands if you needed all new equipment.