This Blue Line Innovations PowerCost Monitor, Model# BLI-28000 drops from $109.99 to $69 as part of the Alternative and Renewable Energy Sale at NorthernTool.com. Even with $5.99 in shipping, that is $13 less than the second-best price we found. Plus, you may be able to get a tax deduction through your state, local, utility, or federal energy-savings incentive program. This device monitors the power usage of appliances allowing user to track energy usage changes. It has received an average 4.3 stars out of 17 reviews. Sales tax is charged in most states.