Great questions that I would be more than happy to answer. The exact model number of the Samsung Galaxy S6 listed on our website is SM-G920P. You can see the model number next to the phone's name on the device's page.
The $499.99 is the rough retail price showing how much you can save when purchasing with TextNow. When the sale ends the phone may slightly rise in price but it would not go to $500. Rest assured, the phone will stay competitively priced.
Let us know if you have any other questions or concerns.