Michelin Energy Saver treadwear warranty/guarantee comes through!

I purchased a set of Michelin Energy Saver (185/65/15) from Discount Tire two years ago. I had them rotated each 7000 miles and ran 40/38 psi. At 42,500 miles they are down to 3/32" tread in the middle and the edges are nearly bald. Even though when I bought mine, 65k was a rating and not a guarantee like it is now, Discount Tire said they would replace them using the 65k pro-rated warranty guarantee. Instead of $118/tire, they are charging me just under $77 per tire. Total OTD price (lifetime balance/rotate, tax, etc) is $398. And Michelin is running a $70 rebate right now plus another $30 rebate for using the CarCareOne Visa. So replacement cost is effectively $298 for a new set. They offered me Defenders for the same price with a 90k guarantee and I said No thanks! I'll come back in two more years and get the same deal again while achieving max mpg with the Energy Savers! Tire cost/mile = $.007... not bad!