I need help. I'm a widow and don't know about this stuff. My geothermal heating/ac unit went out and the technician said it was the fan motor and that it would cost about a $1000 to replace. He said he could put me in a 3 ton Trane unit for $3700 utilizing the existing duct work. Does that seem like a fair price? I thought it did but wanted a second opinion. Thanks.:)

You are so right,, you should get 2nd and 3rd opinions,, get several more different companies to come out and give you an estimate
Where I live the costs of labor or equipment would vary from your area