Answer:
That's a big question with many answers. But if your talking about replacing just the unit outside (assuming you have a split system) it should cost somewhere between $1500-$4500 depending on size and efficiencies. If you are talking about a complete new system including evaporator coil, furnace, and air conditioner then you price will range from $3500 - $6000. Now there are literally thousands of options available on the market today and not enough room on the page to go over them all. The best thing to remember when replacing a system is to find a contractor you can trust. It is far better to have a less expensive unit installed by a professional then to have a high efficiency unit installed by someone who doesn't know what they are doing.