No, not really...
I didn't miss the point at all.
I learn a spell. (Pillum of Fire)
For one season of work (easy enough to get this much) I can get 5 exp in Mastery of that Spell. For that little effort, all PoF cast at me, I have doubled my Form Resistance.
Seems fairly simple to me...but you are complicating things to your ends here...If you have a Parma of 1, I would bet that you dont have a Mastery (or would not get a Mastery) of 3 in a spell...
So lets assume that you have a 1 in mastery...(easily doable in a beginning Magus)
Form: 10 (good specialization)
Parma : 1* 5 = +5
Total resistance is as follows versus the spell:
(My example): 25
Eriks Example: 30
Okay thats not too bad...
Now lets look at a Magus of advanced years...
Darius of Flambeau-
Parma: 5+1 Specialty in Corpus (eliminated for arguement sake)
Mastery 2 (Clenching Grasp of the Crushed Heart)
Resistance would be 55
versus the spell.
Total would be 80
And he is only 87 years old.
Now if the first Magus were to learn "Twist of the Tongue", it would cost him one season (5 exp) to Master it.
To Raise his Parma, would cost him 10 exp. Maybe one season, maybe two. If he had a Mastery already it works out the same. Okay, again thats not bad. Its pretty balanced...but its a starting Magus, so such things tend to be.
...Learns the same spell (yeah he has it already). Five Exp to Master it.
If he wished to raise the Mastery because he has it..10 exp. Not too bad.
To raise his Parma:
Eriks example Doubles the Parma...(versus that spell)...thats a HUGE jump in resistance. I feel doing it this way is unbalancing...hence my ORIGINAL question.
(Erik, please don't take all this as a dis...I am trying to work this out using your example)
Erik I agree with your assessment of similar spells..(though one of my SG takes the 'other' approach...
Well that's your choice. It might be useful if you were invisible...