$100 million a month is nigh impossible, unless you're including the double pay for who actually flew it as well, which isn't right.

I'll even assume $400/hr average pay rate, which is way higher than it actually is, and it still doesn't work.

100M / 400 = 250,000 hours paid out.
250,000 / 5.75 (I'm assuming a little higher than minimum day here) = 43,000+ DAYS paid out as 23M7 IN ONE MONTH. I do not believe that there are that many 23M7 payouts going out, no way. That's over 14,000 three day trips.

Most of those 23M7 trips are going out as double pay whether they use 23M7 or not. You can't count the double pay in the math of what 23M7 is costing the company, only the single pay to the harmed pilot.