A while back, there was an episode of TV show The Profit (Marcus Lemonis) that went to check out a sign-making business in S. Carolina.
I don't really want to comment here on the dynamics of the episode (or its negative outcome) but it would certainly be interesting for you to watch and take note of a full-service signage operation that is VERY successful and thriving.
http://tvruckus.com/2014/12/01/the-profit-update-on-marcus-evaluation-of-asl-signs/
Sorry, I don't have a link to the actual episode (DEC. 2014)