Dealers only sell new autos to capture the service business, trade-in inventory and manufacturer floor plan financing. In the case of Maserati, servicing costs are inline with Ferrari making it a service cash cow!
Incidentally, Maserati used to be owned by Ferrari, although now I think it is owned by Fiat
In 1993, Fiat acquired Maserati from De Tomaso, but a 50% stake was sold to Ferrari in 1997 -- however, at the time, Ferrari had already been under Fiat's umbrella as a sister brand (since 1969).