you referring to "other sellers on amazon"? cuz they're listed as an "Apple Premier Partner" which one can only assume means exactly that...
No need to assume, just read their shop description
https://www.amazon.com/sp?_encoding=UTF8&asin=B07BTS6H4W&isAmazonFulfilled=0&isCBA=&marketplaceID=ATVPDKIKX0DER&orderID=&seller=ATQQBVXK188KS&tab=home&vasStoreID=Expercom is an Apple Authorized Premier Partner and Authorized Service Provider with locations in Utah. Since 1997, Expercom has sold and serviced Apple products, including Mac, iPad, iPhone, Apple Watch, and more. Expercom is one of the oldest Apple Authorized Dealers, and one of the few dealers authorized by Apple to sell on Amazon.com.
"We think Apple is an amazing company with amazing products and services. We are a lot like you: we love when we get to open up the box of a brand new MacBook Air, a new iPad, or the latest iPhone. Since 1997, we have been privileged to help bring these incredible products into the lives of our friends and neighbors. Our relationship with you doesn't end after you buy your Mac, iPhone or iPad from us."