normally if a company needs a map for a brochure or the like, they would just call their advertising agency - they wouldn't think of contacting a cartographer. So if you wanna do stuff like that, you should probably send samples to agencies. But I'm afraid that mearrin is right about the pricing, unless it was a very special product no-one will pay for all the hours that go into a map (unless of course you're a well known artist - then people will pay anything).