Costco has sale event. Get a set of 4 tires, you will get 40off for Goodrich and 60 off for Michilin.
There is no labor cost in Costco wholesale. All price are inculuded in their tire price. If you don't want them install the tire for you, you can get 11 off for each tire. They do life time rotation and balancing, free steam valve, no recycle fee charge.
Usually, if you change your tire in speedy, midas, or CT whatever. They charge $8 for balancing, $3 for monting, $3 for steam valve, $3 for recycle your old tire, and life time rotation and balancing, sometimes, is a must to buy for 20 dollars.
Totally, you will spend 100+ for a set of 4 tires. It's pretty ugly of them that when you asking for the price. They never tell you those fees. They only tell you how much the tire is. They are jerks anyway!