My first post. Hello everybody!

I have a Trane XB80 gas furnace - appox 5years old. The thermostat is set on 80 but the thermostat's thermometer shows about 60 in my cold room. The green aux light stays on until I move the thermostat to about 60. I notice today that - what I guess is - the blower unit in the attic humming but there is no air coming out any of the vents.

My question is:
1) could it be a bad blower? Bad fan?
2) when I call for service, what questions should I ask to avoid getting ripped off? It seems just a house call is running between $30 to $95 without labor/parts.

Thanks.

Those are cheap prices for a service call in this area. It is probably the motor or a control relay.