Just put in my PS4 copy this morning and its only $15 to upgrade to the remaster.
If you received a digital copy through PlayStation Plus you are eligible for the upgrade also
Currently if you do not own it, its $75 to buy online.
I just had a look at preowned copies (CEX/DSE) and it should cost you around $15.
Existing owners of Horizon Zero Dawn (PS4)* and/or Horizon Zero Dawn Complete Edition (PS4, PS5) can upgrade to the digital version of Horizon Zero Dawn Remastered on PlayStation 5 console. This includes fans who added the game to their libraries during PlayStation’s Play At Home initiative.**
*Owners of the Horizon Zero Dawn PS4 game disc can access this offer by inserting the game disc into their PS5 console (and will need to keep the disc inserted each time to play the game). PS4 game disc owners who buy the PS5 Digital Edition disc-free console will not be able to access the upgrade offer.
**Redemptions via PlayStation Plus are not eligible to upgrade.
https://press-start.com.au/bargain-guides/2024/10/31/horizon….
Paid $9 for PS4 copy when it was on special. Great game. Will get a forbidden west to play in future.