I hear you and feel your pain on the non sign, non tax, non insured etc guys...they have killed the lawn business, close to killing the paver and landscape install business. I'm not as big as you, however I tell potential customers right up front if price is how you determine who your hiring I am not the guy for you, then follow that up with laminated copies of my licenses and insurance certificates to show EXACTALY why I am more than the cheap guys. Personally I don't give out pricing unless I am bidding a job.
I support and am trying to get a statewide landscaper license, decal on truck(s), that can be enforced by local PD to make the business competitive for all. Not to be a complainer but just griping and trying to build support for the statewide license.