How much does this cost to the nearest dollar?

AprilAire 50 Low Voltage Current Sensing Relay for AprilAire Whole House Evaporative Humidifiers
BUY WITH CONFIDENCE This genuine AprilAire HVAC part helps optimize the performance of your AprilAire Whole Home Humidifier and protect the humidifier's precision electrical components from feedback current ENSURES HUMIDIFIER OPERATION only when the furnace blower motor is running to properly distribute humidity throughout your home CAN BE USED in conjunction with either an Automatic or Manual Humidifier Control/Humidistat COMPACT SIZE with dimensions of 1 inch x 1.44 inches x 2.75 inches VOLTAGE RANGE of 21-24 VAC, 50-60 Hz and Sensing Current of a minimum of 4.0 amps Current Rating 

Price is $43.00

Price: $42.92