Well that is like those anecdotes of 40 a day smokers living until 100 isn't it?
Everyone ridiculed the price of that food linked above but look at the ingredients.
Salmon, Haddock & Blue Whiting 60% (Freshly Prepared Salmon
21%, Dried Salmon 16%, Freshly Prepared Blue Whiting 11%, Freshly
Prepared Haddock 10% & Salmon Stock 2%), Sweet Potato (20%),
Potato, Beet Pulp, Peas (6%), Linseed, Omega 3 Supplement, Minerals,
Vitamins, Vegetable Stock, Asparagus (0.2%), Glucosamine (170 mg/
kg), Methylsulfonylmethane (170 mg/kg), Chondroitin Sulphate (125
mg/kg), Nucleotides, FOS (96 mg/kg), MOS (24 mg/kg)
Compare that to Dr Johns gold.
Cereals, meat and animal derivatives (minimum 14% chicken), oils and fats, yeasts, milk and milk derivatives, oils and fats, minerals.
It really isn't hard to see why one is dirt cheap and the other is not.