If you already have gta5 on your ps4, is it worth it to get gta5 (is currently reduced to 15 euro) for your pc to play with mods (and higher graphics)?
No.
Definitely no!
Thrown out money, stay healthy
Dan of course always depends on what and how many mods you have available for a game. Most change the game, if at all, minimally, or even make it unplayable.
Only for better graphics would I not buy the game again.
Here you have a few mods
But as I said, it's usually just gimmicks. Unfortunately, I don't know now whether there's a mod for GTA 5 that will make GTA a completely new game.
Here's a positive example of what mod developers can do with a game