Maximize (+150) and Empower (+75) = + 225 Spell Power
That's a net gain of ~66% spell power (Force) in my case <-- Remember that this number will never change in the calculations - it's a static increase.
Maximize (+25 spell Points) + Empower (+15 Spell Points) - Enhancements (15 total) = +25 Spell Points
Meteor Swarm costs 40 Spell Points base and 25 spell points additional for Max/Emp for a total of 65 Spell Points - that's an ~63% increase in spell point cost.
SO... you get a 66% increase in spell power for a 63% increase in spell point cost on one of the highest spell point cost spells in the game (Meteor Swarm) - and it costs you 2 feats and 12 AP.