I'm trying to parse the idea of "a collective agreement" but can't fully wrap my head around how that would work.

It seems to me more like the lack of a "Walmart Law" is a result of e.g. lack of economies of scale and other economic structure, rather than some collective agreement. (If it was profitable to break out of that agreement and start a "Walmart Law", it seems we'd see that happen pretty quickly?)

But if you know more about this and I'm off the mark I'd love to learn

Every fortune 500 company has a team of lawyers working for it.

Lawyer rates are extremely high variance, and the NYT is not hiring anywhere near the median. White shoe firms break $1000/hr routinely.

My understanding of the price/scarcity dynamics here are that people want lawyers with significant experience, there are a relatively small number of openings every year for BigLaw associates that provide access to that kind of experience, and they hire almost exclusively from the T14 schools.

If you want a random lawyer, you can get them very cheap. But if you're doing M&A or serious corp litigation, you're looking at a much smaller and more expensive pool of candidates. I was shocked by how much our M&A lawyers cost.

All this is to say: the median might not be telling most of the story here.