But not every act has the fan base to toy with creative ticket pricing. ???It???s a balancing act and one of the hardest things we have to do in our jobs,??? says David Galea, a 12-year booker at The Agency Group, which represents such bands as Muse, Nickelback, The Black Keys and Paramore. ???If you???re overpricing your artist, ticket sales are going to suffer, but you don???t want to undervalue