Hi Graeme, off the top of my head I can post a few links from the Design Council, who publish an annual report on the value of design and promote the use of design for business success:
http://www.designcouncil.org.uk/en/Abou … actfinder/
http://www.designcouncil.org.uk/en/Live … c-climate/
I would never try to teach anyone how to suck eggs on how to sell as you all have far more years experience than me, but I believe in stressing the value of the work you produce, talking about the quality of materials you use and a professional install.
Also showing the client if you’re designing a sign that will last a few years, is it really expensive when you break down the price per year?? and also if you’re designing an identity for the client which they will probably/could use for their stationary print, are we really getting a fair price for the level of work we’re providing??