Magic Armor Prices

In the PH, it states that armor prices double for each size category larger than medium and halve for each size category smaller than small. My question is, does this increase/decrease apply to magic armor prices as well, or just to mundane and masterwork? Is it the reagents that make the armor expensive, or the enchantment itself?

I would say the armor is the only price that goes down by half. The reagents to create the armor would still be required to cast the spells to enchant it, as would the spells themselves. So no, you can't get +4 armor for 8000 gp.

However, that's what I think. I can check with the Sage to make double-sure.

EDIT: I sent in the question - apparently they hadn't been asked that before...

That was my gut instinct as well. A bit disappointing, but probably right. I believe the halving applies to special materials like mythril and adamantine, though.