When you purchase, state the phone is a gift so that it is not registered to your account. This way you can save it as a spare, sell it, or give it as a gift.
When the phone is registered to an account you will/the account will get 1 year of amazon prime.
Amazon price is $99 per year. The phone with Amazon prime is $130. So, if you want Amazon Prime… its like getting the phone for $30.
If you have Prime already, this will extend Prime an additional year!