A:AnswerGo to your cell-carrier's website and engage the chat feature. I've had similar questions and when I asked a tech with my carrier (AT&T) they were able to tell me almost exactly how much I would pay. Make sure you ask about any up-front charges, carrier fees and and taxes. (Understand the $44.90 does not include a monthly carrier fee which is usually another $20 a month.)
OR... You can still just pay cash up-front for an "unlocked" device and simply activate/add a device to your current cell plan later. That's how I added my Apple Watch that I bought at Best Buy when it was on sale about a year ago.
Hope this helps.
