Spell Jammers should increase resource cost instead of casting point cost

[acoustic hull]

Low tier spells have much lower mana : costing point ratio than higher tier spells. For demonstration, this is the progression for tactical spells that cost mana:

Spell Tier, Mana Cost, Casting Point Cost, Mana : Casting Point Ratio
1, 10, 15, .67
2, 15, 20, .75
3, 30, 25, 1.2
4, 45, 30, 1.5
5, 80, 35, 2.3
6, 100, 40, 2.5
7, 150, 50, 3
8, 200, 65, 3.1
9, 300, 80, 3.75

So the current implementation of spell jammers is actually much more harmful to low tier spells than it is to high tier spells. I think that seems wrong?
I think it would be more interesting if

1. Spell Jammers gave you incentive to use low tier spells later in the game
2. Spell Jammers did a better job protecting you from players who have access to high tier magic than from players who are stuck using low tier magic

So yeah. Spell Jammers should increase the resource cost (e.g. Mana/Souls) of tactical spells, not the casting point cost

[vernal blaze]

The main issue is that later on mana is rarely the limiting factor of spell casting and anyone with a mana surplus would be largely unaffected by a spell jammer.

[acoustic hull]

I think an argument could be made that having the ability to power through a spell jammer at great cost, as opposed to there being literally no counterplay at all would also be a good thing.

[wooden jewel]

I'd argue the counterplay is razing the spell jammer. I can't think of a game where I didn't end up with thousands of surplus mana by the end game, so that's less like there being counterplay and more like the spell jammer becoming obsolete.