I don't think that forcing players to spend in-game points to save is a good idea. The only way for that to work without being frustrating would be making points easy to get, or making saving not cost much at all. Though then it would be pretty much useless to have it in the first place.
Lets use an example if they make dark souls 4(I don't think dark souls 4 exists yet), and have this feature. The game by itself is rather unforgiving and it's easy to lose souls as it is, but to top it off you pay like 2,500souls to save? It would make the game not even worth playing. Plus if you die, and have to go back like three hours because you didn't want to pay all the points you just got. Well that would be no fun at all!