Activation and deactivation will be charged on my sprint account?

I purchased the "famous" galaxy s6 edge plus with contract. Regret it! I miss the iphone and also made the mistake of buying it plus. If I sell the galaxy & buy the new iphone full price on the sprint store, will they charge the deactivation of the galaxy and activation of the new iphone?

As long as your phone/account has not been shut off, you can activate as many phones as you want on your account (one at a time of course).

If you phone/account has been shut off for non payment, you will have to pay off the outstanding bill before they will activate a new phone. If the phone you have now is still being paid for, you will not be able to sell it to anyone, until it is in fact paid in full. Otherwise the buyer will not be able to activate it on their account until it is paid for in full.