The logical (and accurate) stat importance for Mages is rightfully Spell Power > all else. It’s obvious when you stack spell power gear and use frostbolt, the increased DPS is there.
I found this Base Stats Calculator on a Barrens Chat (cannot link) 
) page made last year. It’s pretty cool and made me realize how little intellect has an effect on spell criteria. There’s not a lot of spell power gear out there right now and I looked at BiS will give me a better idea, but I am wondering if, in Classic, there’s enough intellect to stack out there by level 60 that truly affects the degree of crit you can attain.
I’m only level 34 right now, of course, but my intellect is 164 which creates a … ‘whopping’ 2.76% spell crit; nothing to write home about.
I suppose that intellect is only relevant in having a larger mana pool (which is big for mages anyway.) I suppose I’m just opening up this discussion out of curiosity.