That completely depends on which radio station, in which "market" area, at what time of day, and ultimately on how many ears are likely to hear it. Every network, every station, every city, and every...
This site gives some clues. But I imagine the range in prices is based on how many are ordered at the same time. http://www.boeing.com/commercial/prices/
It depends on the time (e.g. Prime time will cost more), what's on the telly. More people will watch the World Cup final than will watch daytime TV, so World Cup final advertisements will cost more.
