Same with me. Had to pay another $19. Almost half the shipping. But...where I live some shops just refuse to ship ammo to me. So..part of the cost of not living within the city limits of a large town I guess.
In my case it has to do with UPS not able/willing to ship dangerous goods to my address. Purolator would but cost more. Guessing it is because Tenda has an arrangement with UPS and not Purolator. In a way I'm ok with not using UPS. Always a poor shipping experience with UPS so I try not to support them.