I'm sure you're right, in some cases at least, Pat, but I've had better luck with Discount Tire Company that anywhere else. In fact, I've been buying nearly all my tires from them for over 20 years. They've always been the best service; even repair flats free on tires that didn't come from them. They used to always be the cheapest, although sometimes that isn't the case now. However, if you find a price lower than theirs, they'll beat it. And at the present time, they're also the closest tire dealer to me.
I did do some shopping this time; didn't find anything on the Internet to beat the local prices. Sears was about $6 cheaper for the set of 4 and the local Ford dealer was about $10 cheaper, so Discount Tire knocked off $14 from their original price. National Tire and Battery (NTB) price was just ridiculous; about $20 per tire more. Sears' and the Ford dealer's prices did not include any flat repair in the future or re-balancing on request.