I doubt it will have particularly high hardware requirements. It's built around base PS5 and even Xbox Series S, neither of which are very powerful systems compared to common PC gaming hardware.

We're talking about RX 6700 or RTX 2080 levels of performance for PS5 (which can be found used for around €/$ 200 with a bit of luck) and RX 6500 to 6600 (XT) for an Xbox One S equivalent, which is a bit cheaper. CPU performance isn't even worth going into, since it's trivial to match and exceed with a PC, even on a very modest budget.

This isn't just theoretical. I built a cheap PC around a used RTX 2080 a few years ago to match console performance (just in time for the Starfield release; I actually had a great time with this game) and it was pretty much spot-on with a bit of an advantage for the Nvidia GPU depending on the title - and with prices back then, I actually managed to build the entire PC for roughly the same price as a PS5 or Xbox Series X.

Even if we aim for the PS5 Pro as a recommended target, we're talking RX 9060 XT and RTX 5060 Ti (16 GB versions), which can be found for less than 500 bucks with a bit of luck. Not cheap, but not outrageous money, especially if dropped into an affordable AM4 system. The rumored 30 FPS limit even on PS5 Pro is very likely due to a lack of CPU processing power, which isn't an issue on PC.

Rockstar has every interest in the world to make this game run on as many PCs as possible, since GTA Online in particular is their main cash cow and they are hoping to convince as many players of GTA V Online to migrate over to the new game and buying as many Shark Cards as possible to speed up the grind again.

For as much as one has every right to hate the company for its labor practices and how it's treating the gaming community, the studio is employing some incredibly talented programmers and artists who have been known to cleverly squeeze every last bit of visual fidelity and simulation complexity out of relatively limited hardware (apart from the abysmal GTA IV PC port, of course).

This is speculation, of course. The PC port might be terrible, but I think after RDR2, this is unlikely.

So, in short, you won't have to spend two grand on a PC to play it, even in today's crazy hardware world. Chances are, if you already have a somewhat decent PC, you might only need to upgrade it a little. What are your specs?