[Ualaa]

Well, I'll echo the core stuff sells more. I picked up the Player's Handbook, Dungeon Master's Guide and first monster book for 5e. And the equivalent for Starfinder. I'll likely do the same with PF2 at some point.

But our group is sticking with the original edition of Pathfinder. We literally have all the books, and between the group have 2-6 copies of each of the hard covers (one of my players also has a full set, others have some here some there).

Path of War (and PoW: Expanded), Ultimate Psionics, and Spheres of Power, Spheres of Might, Champions of the Spheres (and the upcoming Ultimate Spheres of Power) are also rather popular.

Far too much of an investment to move on, just because there's a new system. Sure, we were in a similar point with AD&D 2nd, and with 3.0/3.5, 4e, and moved on eventually. But we didn't do that edition hop until we had both run out of content for purchase of the system and actually played all the content.

I have 29 campaigns I'd like to run, with the Pathfinder 1e ruleset. Of those 12 are ideas of campaigns I'd like to do and the rest are store bought (or more are actually Kickstarter supported) full campaigns or lengthy adventures that can be added to, to create a 1st to 20th run.

On top of that, two others in the group have tried their hand at being the DM, so they will likely want to run something themselves too. I know, after we finish "The Blight", one of the two has a campaign he wrote for us which will be next, and then my ambitious campaign after that one. In his case, he's modifying a 1st edition adventure for our early levels, then will run a campaign (and modify to PF1e rules) he wrote for 4e but that we never played, then something that was written for DnD 5e (again modified to PF1). So, he's plundering other editions, and actually the entirety of his 1st-25th campaign (gestalt/mythic) will be originally written for not PF1 but be played using the PF1 system.

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My next campaign (one of the 12 that are my own), will be ambitious. I have the idea for two campaigns really, one starting at lower levels (maybe 3rd, just because it's more fun once you have a few more options), and will very loosely follow the original Mistborn novels. Loose, in that the aren't Mistborn or the need to consume metals, but a dystopian world with a ruler that many take to be a god.

Eventually the group takes him out, but he was holding a darkness at bay. Then the second campaign, starting around 20th, with the same characters and going to 50th... a kind of Time of Troubles thing, with powerful beings (the group included) trying to be the survivors and thus the Pantheon of Gods going forward in that campaign.

It will of course have to be Gestalt rules, and upon taking out that first "final" boss, the group will start to become mythic.
Why not use all the systems?

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Anyway, tons of material for this first edition of Pathfinder; most campaigns or adventure paths take us 1.5 to 2 years of real time to do.

We play weekly, but modify encounters to be a challenge for a group of power gamers, and add things, tweak things, etc.

Too much content, not done, to move on.