Puzzle me this ....
I bought two tires on E-Bay from some company on the west coast, I am in the east. The guy charged me $10 for each tire for UPS shipping. That may not reflect his cost to ship, but it can't be too far off because he was the least-cost seller of the somewhat popular tires.
A couple of days later I bought a new Akront rim from a guy in New Mexico, private seller. He took the wheel to the Post Office and got sticker shock there when he asked how much to send it, then it took it to FedEx, who charged him $47 to send the wheel to me (I agreed to pay half).
Two tires weight a lot more than one aluminum wheel and take up probably 3x the space on a truck, but a company can have them shipped for twenty bucks whereas a private individual has to pay nearly fifty for the wheel to go on its way. So, howcum?