How much did radio actors make?

There were certain actors on radio who stayed very busy, but never (or at least rarely) starred on programs. An example would be Herb Butterfield on Dangerous Assignment. He was on every week, but only for a few seconds, usually at the beginning of the program or for a brief phone call from star Brian Donlevy later on. I wonder how much he made for that role in today's dollars. Another example would be Junius Matthews, whose distinctive voice got him lots of bit parts in various radio programs. What was hit take for those spots?