This is one of the best questions in the sign industry. In my opinion I think it would depend on the job and the equipment used to perform the survey (i.e. Boom Truck). I make it clear that the information obtained is property of our sign co. I make it clear that the survey information could be purchased if the customer decided to go elsewhere. The customer only gets an undetailed estimate ( NO measurements, electrical information (i.e. ballast, transformer size) COST ONLY.... Again, this really is up to the sign co. Hope this helps. Good luck