I’m sure there is, or will be, a district court case that accompanies the ITC case, but with overlapping but different asserted patents. Standard procedure. And no Amlaw 100 firm is charging more than $10m for that case, and discovery isn’t running a million a month. Remember, the plaintiff has almost no documents to produce (conception, reduction to practice, industry requirement, and that’s about it). Taking depositions and sending discovery demand letters doesn’t cost a million a month.
As someone who knows Amlaw 100 very well, yes they do and yes it does. We usually quote $10m as a starting point for a 4-patent case against sophisticated tech respondents for a case going all the way from diligence to hearing.
Look at the respondents in this case. They will dump literally millions of pages on the complaint, which will all have to be reviewed. Even if the firm hires outside reviewes to cull it down to only the relevant stuff, it's still an expensive task. And in my experience, outside reviewers are rarely worth it long term.
But more importantly, the infringement and validity contentions that have to be prepared at the end of discovery are the expensive part - they're very important, huge, and very time consuming to create. And because of the compressed schedules at the ITC, those things have to be done during discovery. Then the expert reports, even more important, even bigger, and even more time consuming. A lot of time is spent preparing for expert depositions.
4 Amlaw100 attorneys, average rate is $500/hr or so. Plus a paralegal at $200. That's $2200/hr total. Full time (40hrs per week) that's $352k in law firm time alone for a month. But end of fact discovery and expert discovery is not merely full time - I easily bill 60hrs per week during those times, sometimes more, so the firm time can easily cost $500k per month. Add in experts which can vary from $200-800/hr, add in international travel expenses (most respondents here are foreign) and internal hotels with business centers, deposition expenses (court reporter, videographer, conference room), interpreter. $1m per month is not hard to get to.
Also, yes there are district court cases, there always are, but those are usually stayed pending the ITC. It's statutory.