My experience with discount and Costco are this. I called discount for a price on good year 6-14's for a friend coming to casa grande az. It was a shock the price I was quoted compared to what I had just paid for ours in Wenatchee from an old time tire store. Then I bought the Michelins for our chev and all 3 were almost the same with the old time store a few buck per tire less but at the time of install the price was less than the quote and I had complete control of the date the tires were made. So now buying the new defender Michelins for the GMC discount and Costco were the same but Costco takes good care of warranty from others I have talked to. Plus for the first tire install for us in many years the Costco installed did the torque correct, not over tight using the impact wrench and doing the fake click, click using the hand torque wrench and not turning the lug nut any. happy with Costco's.
The Costco store ground in east Wenatchee wash. was my play area as a kid.
chevman