Why 2 4 6 8 10 rather than have the cost and 1 2 3 4 5?this could be interesting, and would allow for a short rest recharge of power pts.
from levels 2-11 you have 2 slots of the highest level you can cast that always recharge, what does that look like in mana?
if they cost 1 per level
2 1st level spells is 2
2 2nd level spells is 4
2 3rd level spells is 6
2 4th level spells is 8
2 5th level spells is 10
you can track that to level and say you start every day with your level (to a max of 11) in power pts and you regain them on a short or long rest, you can spend them on any power you know.
starting at level 12 that gets problematic though
The big problem with power point systems is how spamtastic they get, especially in combat. There are normally optimal spells that you just cast again and again. Eldritch Blast is fine - but limited resource versions make the game less interesting because those are your shining moments and shouldn't be all the same. And short rests don't really work in 5e.However, the short-rest spell point refresh is so excellent. So mechanically balanced. So simple. So intuitive. So narratively appropriate. The spell points are so much better, it is worth having the Players Handbook.
Indeed, now wish all the full caster classes − Wizard, Bard, Druid, Cleric, Warlock, Sorcerer − would use the short-rest spell points instead! It is so much better.