One of our friends just replaced his gas furnace and it was over $5,161. That was supposedly with a 10% discount because he took our a one year *service plan* for $250.00. He has a three bedroom ranch house which probably is around 1800 sq. ft. or a little more.

I'd be inclined to deal with a local HVAC company. Can you get some referrals from your neighbors on who they have used. Get more than one bid.