Along those same lines, the LW bracers enchantment, Fur Lining: Attack Power, is apparently worth the same number of enchant points (15) as Greater Assault.
That's +50AP vs. +130AP, an enormous difference.
The point values of these high level, self-only profession enchants need to be bumped up to 20. (Or at least increased by a value you deem appropriate.) Although I'm obviously not familiar with your formulas, this seems like an easy fix.
With so many people gear checking WoW-heroes when forming PUGS (and looking only at the GS number, for the sake of saving time), I think it's important to get this kind of thing right.
p.s. Have you thought of working w/the folks who designed RAWR to create a more balanced, accurate measurement of GS, specific to class, spec, etc., and not just going off of Blizzard's gear labels, which can be so easily manipulated?
(For example, I throw on my 245pvp trinket before logging off each night, because my DM Card: Greatness (a full 120dps boost (base) over the former) is only level 200. That way my overall score is higher when I'm trying to find a group.)