The ABA ought to bring price pressure through the accrediation process. Create a formula that ties bar passage rates, starting salaries, employment upon graduation, and average debt load together. Schools with low passage rates and high unemployment must reduce tuiition or class size. This will lead to some reduction in resources for schools which already have few, but there are a number of ways to restructure a law school to meet these needs.
Man, I really like your ideas here, but the sad truth is that such action would ONLY lead to even more legal action against the ABA, not lower tuition.
Law schools charge what they do for one reason: they can.
The fact that any and everyone who can fill out a FAFSA form can gain instant access to $150k in federal funds is also a big reason for the proliferation of law schools and skyrocketing tuition rates (and that goes for all colleges and universities, not just law schools). I'm not saying that the alternative is a better idea, but there's no way that arbitrary tuition caps at law schools are ever going to become a reality.
Hell, if anything, schools like Yale and, especially, Harvard (who, IIRC, has $20 billion in endowments and $5 billion in endowments just at the law school) should lower tuition as soon as any school...and we all know THAT will never happen.