I think it really depends on what they all do. A resolution and fps update shouldn't cost anything but if they put in a lot of work then I don't mind paying (not $70 though).
But why not both
Ghosts of Tsushima unlocked the framerate and released a native PS5 version.
Many people whould be happy just playing the PS4 version in 60fps. And all the Devs would have to do is open the config file and change 30fps to 60fps.
I'm not saying Sony shouldn't be allowed to do Remasters and improve things and charge for the work, but the fact that they refuse to just do a unlock framerate patch for the original versions seems like corporate greed. I have praised Sony for the patches for God of War, Horizon, Days Gone, Last of Us 2 and Ghost of Tsushima. But this Uncharted remaster just looks like corporate greed.