newegg offers the P3 Kill A Watt Electricity Load Meter and Monitor, model no. P4400, for $16.99. With free shipping, that's tied with our expired mention from a week ago and the lowest total price we could find by $3, although we saw it for $2 less last June (since expired). This meter can be used to monitor the electricity output of household appliances and features an LCD screen displaying voltage, line frequency, and power factor.