Discount for me has been great.
I have also used Costco. That was ok too - but generic.
I sold a set of wheels (with mounted tires) off the E9 to a buyer in NJ.
I asked the Manager at the Discount store I go to for some advice on packing them up (I was planning on taking them to FedEx myself).
He offered to ship them to the buyer and just charge me for what it cost him to ship.
That saved me over $100
I don't even 'shop around' for tires any more.
And with 7 cars and 3 trailers....