Very rare according to this SS post:
C70 history:
1998 was the first year for the new Volvo C70 coupes. The 98's came loaded with options including dual power heated seats, a premium Dynaudio stereo system with an in-dash 3 disc cd changer, traction control, etc. The car has a 2.3 liter inline 5-cylinder turbocharged engine and produced 236hp/243 ft. lbs. torque from the factory. The copper color found on the car for sale is known as Saffron Metallic and was extremely rare for the North American market. Only 135 +/- C70's were sold in the US ever. Of the 135 less than half were equipped with a manual transmission.