I disagree. Anything I know of with powerful build is not a humanoid -- Goliath, Half-Giant. This is important.
There is an item in Magic Item Compendium called Strong Arm Bracers. For 6k gp, gives you the weapons benefit of powerful build (and thus doesn't stack with it).
So, a medium human for 6k gp can wield the same large sword a goliath can. However, a human can also benefit from enlarge person, ending up with a Huge weapon. The goliath must rely on Expansion, a psionic power and thus off the bat likely less available. Add to that the fact that without added power points, it has duration round/level -- ie, 1 miserable round at the base cost --it's also much more difficult for the goliath to replicate the human's ability to pop a CL 1 potion for 1 minute's (one fight's) worth of growth.
Maybe you think the cost of the bracers outweighs or equals any extra cost for psionic tattoos for the goliath (which reminds me, the tattoos will cost double since it's a personal power), and want to just cover your eyes and pretend LA doesn't have a "cost." It still means Goliath and Half-Giant (all of this applies to them as well) are no better at overcompensating than any regular humanoid.