So I am playing a grappling build with a character who doesn't have improved unarmed strike (I took dirty fighting, I have 10 dex), but he does have natural weapons. While I know he won't gain the +2 to damage, is there any reason he WOULDN'T gain the +2 to grapple? It states that it doesn't apply to natural weapons, but I don't necessarily have to grab with the natural attacks themselves.
And, provided the previous is true, if I transform into a creature with grab and land a hit, will the following grapple roll gain the +2?
Also, can anyone tell me why the errata made the bonus cost a +3? I understand why they didn't want it a +1, but a +3 seems too much to me when there's something like the gauntlets that only cost 4000 gold.
I assume this is about the armor enhancement and not the weapon enhancement.
You'd the +2 to grapple. The wording is a bit strange, but in general you grapple with your whole body anyway, not your unarmed strike. (For a similar case, note that a +1 amulet of mighty fists does not improve your grappling ability because grappling is usually independent of attack types.)
I *might* see a case for disallowing the bonus if you did the "grab with one limb at -20" option from the grab universal monster rules, but even that could go either way.
I don't know which gauntlets you refer to, but IIRC +3 was intentional (and largely booed at the time of the erratum).