In the U.S. it varies by region, but mid-quality panels are usually quoted at $2.50 to $3.00 per watt installed (before subsidies). Tesla Solar is advertising $

In the U.S. it varies by region, but mid-quality panels are usually quoted at $2.50 to $3.00 per watt installed (before subsidies). Tesla Solar is advertising $2.00/watt nationwide but there are some questions about their responsiveness in actually getting anything installed in a timely manner. Outside of CA most people are only paying $0.10-$0.13/KWh making payback rough unless you have a large state or local subsidy on top of the federal 26% tax credit.