I agree with the clever marketing - you are spot on blacklabrador!
If you are a little hesitant on feeding a top premium food like Royal Canin, Hills Science Diet, or Eukanauba (due to price), then I have heard a lot of vets praise Eco Pet. It is all natural, no preservatives etc... here is their site. I have heard great things abou this - but I haven't read the label directly. And I know it is about a quarter of the price of the top brands.
http://www.ecopet.com.au/index2.html
Maybe worth investigating anyway - but I still think the permium brands are unbeatable! I personally really notice the difference in their wellbeing (coat, allergies, general health etc).
Also - with the premium foods, ask for a breeders card and you will get every 10th bag for free!