BRK 7030BSLA 120V AC/DC 3-IN-1 SMOKE, CARBON MONOXIDE & LED STROBE ALARM WITH 10-YEAR SEALED LITHIUM BATTERY BACKUP

This is the detector I need for my hook up that is hardwired onto the house circuit. The Covalin sales associates were very friendly and efficient. The one unfortunate thing is the price of this unit. Why does the price have to be so high???