Hence the second part of my post. If there aren't any construction differences, then simply being associated with Firestone is enough to warrant reducing the price by 50%, or it points to Kumho overpricing the tire when not sold as a private label.Not necessarily true.
A lot of Costco's "Kirkland Signature" items are nothing more the repackaged name brands. The exact same product. No cost cutting, except advertising.
At most the packaging is different (like a sidewall branding on a tire). To some people paying for a name brand (even though it is the exact same product) is important to them.
The BIG Brands Behind Costco's Kirkland Signature Items
Some of your favorite name brands may have cheaper options at Costco...hip2save.com
Which, honestly - Firestone being Firestone - I can understand, but $175 for a basic touring tire from Kumho is way beyond what I'd pay also given that's getting close to Michelin/Continental pricing.