Should get a 2nd opinion

You should contact another local air conditioner reair service for a 2nd opinion. Our air conditioner has been in use for 18 years, never get any service in the past. Its outdoor unit broke down yesterday. I went online at our local BBB page, and found one BBB certificed air conditioner service near out home.  They sent in a van as an emergency cal, and worked on the unit, changed copactor (broken), contactor (near broken with may be one more year life), add refrigerant.  The total bill is $501 (including $135 after hour servicde call, since it is Sunday).