If you have Playstation Plus Destiny 2 is available as a free download. This is part of the monthly games received with PS Plus , so users will be able to play the game for free as long as they continue to pay for PS Plus.

This move to make Destiny 2 free is most likely a strong marketing push by Bungie and Activision to potentially hype new players up into buying the upcoming Forsaken DLC.
If you are a new player picking this up for free though, be wary as Forsaken requires expansions I and II to play.
Destiny 2’s Forsaken releases on September 4th for $39.99.
There is also a version of the game available for $60 that comes complete with both expansions, the game, and Forsaken. The annual pass for content post-Forsaken is an additional $35, or you can pay $70 for Forsaken and the annual pass.