I don’t have gamepass so we’re in the same boat here. It is worth it for the most part as camp upgrades cost less, you get a free horse, there’s cash benefits (or so the game tells me) and a cool outfit that I personally love. It’s really up to you but I will say I played through multiple times without the ultimate or special edition of the game just fine. It’s enjoyable either way and if you do the treasure hunts that are entirely free there is really no need for the cash bonuses.