User blog comment:Obyvvvatel/Magic resistance isn't effective./@comment-4834593-20130516184044

First, as said already, the title is misleading. If you think Magic Resistance is not effective, at least prove you're right before proposing to reduce the gold cost of high tier magic resistance items.

Second, you don't understand why Magic Resistance currently isn't effective. It's not because it's too expensive, it's because you cannot get enough in a single item. The highest Magic Resistance item has 55 Magic Resistance (Runic Bulwark, 25 of this is Aura), which is a lot less than the highest armor item (100 for Thornmail, 90 for Frozen Heart, 70 for Randuins Omen, etc), while these work with the same formulae for penetration, reduction, etc. And on top of that, armor has a few items that combine with health well (for example Randuins Omen (500 health) and Sunfire Cape (450 health)), while the best options for Magic Resistance and Health are Runic Bulwark (300 health), Banshee's Veil (400 health, but only 45 Magic Resistance (so, in fact, still worse than a Sunfire Cape (which is pretty average for health + armor), while the best MR + HP item)) and Spirit Visage (200 health).

And THAT'S where the problem is. It's not that Magic Resistance is too weak, it's because there are no good build options.