For you guys in the Phoenix area, or that are willing to work in the area there is a new concert series starting up called Greenstock. I went to the meet and greet last night. They seem to have some pretty good backing. They eventually want to turn it in to a nationwide series.
Their booths for the show April 1-3 are $750 for a 10x10, $950 for a 10x20 and $1150 30x30. I might be off a few hundred on these.