[PF] Spell-Storing Armor Spikes for a Grappling Spellcaster

[The Oni]

So, I've got a White Haired Witch/Sohei that specializes in hair grapples. He wears a Spiked Haramaki so he can do extra damage in his grapples (with no ASF chance), but I want to use my spells to their full potential as well. I've got a fair bit of gold lying around and I'm considering spell-storing on my armor spikes. So, a couple questions:

1. Do I get the Spell Storing effect just by grappling? That is to say, when I grapple with a spell stored in the spikes, do the spikes hit and have the spell go off, or do I have to actually do a separate maneuver for that?

2. Would it cost me 2K or 8K to put this on the Armor Spikes? I think it would be 8K, since they won't let you enchant stuff with special abilities unless it has an equivalent enhancement bonus, but I wanted to be sure.

(Note: I am aware that Unarmed Fighter would be better than Sohei for this build but it's too late to change it. I am also aware that Tetori is an awesome grappler, but I'd have to take more levels of Tetori than Witch to get any benefit out of it and then I wouldn't get the White Hair special abilities.)

[Dr. Yes]

That's tricky, but the wording on the spell storing weapon enchantment has two conditions: the weapon must strike your opponent, and that strike must deal damage. You've got the damage part covered, but I'm not sure if "strike" is a strictly defined game term; at least, I've never seen it laid out anywhere. The common meaning of the word certainly wouldn't include grappling, so in the absence of a formal definition I'd rule that you have to make an actual attack to set off the enchantment.

Your second question is more clear-cut: you would need to spend 8,000 gp to put +1 and spell storing on the spikes, as you cannot have the latter without the former.

[The Oni]

1. Well, the wording is that Armor Spikes deal damage on a successful grapple attack. I would think that the act of grappling is itself an attack, thus grappling would deal the damage and trigger the spell. A hug from a dire porcupine would probably deal damage to you, so a similar aggressive maneuver from a human in armor spikes should, too.

2. That's what I thought. Thanks!