A:AnswerOnly way to do this is buying at Apple Store. Best Buy inserts the sim while activating, so it get's activated on your carrier that you bought the phone through.
A:AnswerYes, just purchasing the phone. You will need to activate at home on phone follow instructions. The store will also activate if you want to go there. The payments will be added to your bill unless you pay in full. The bill will be what mobile plan you pick from options.. Around $75.00 per month estimate. You can also transfer your data from Apple phone to Apple phone easy, follow instructions . Thanks.
A:AnswerCricket sells the iPhone X, XS, and XS Max (at least online, not sure about in store) but they aren't a carrier connected with Best Buy, so you won't be able to go to Best Buy to upgrade your phone or plan.