2 of my boys previously worked for Kwik-fit. The profit is around 50% on a tyre so plenty of scope to give discounts. One of the boys now works for a tyre distributor so he gets his own tyres at cost price and thee price seems very low for the ones on is 5.7 litre Monaro.
I have not bought a tyre for many years as with new cars, they generally last up to 36,000 miles although my Toyota tyres look half worn at 14,000 miles.
On 2 Peugeots i had, tyre wear was bad and just 12,000 miles on the front ones.
Longest life were Michelin on a 2 litre Vauxhall Astra which went for 33,000 miles for me then another 3000 miles when my Brother bought it.