Originally Posted by
Bzzt
It's not only the pilot costs, there are many economic factors that make it cheaper for mainlines to outsource flying. Outsourced flying does not cost the mainline anything for MX, fuel, labor costs, aircraft costs, etc. Also there is less liability for the mainline carrier on the outsourced route. It sucks but thats business in the US today.
Mainline usually takes care of the fuel and if they own the planes they probably take care of Mx too. Regionals provide cheap labor.