It's also pretty interesting the prisoners know how much money the prison gets from a company. I doubt I could find any Americans in a private prison that are so versed on the bottom line. I highly doubt I could find many guards that know the administrative details of labor deals.
Meh; there'll be rumors. I have no reason to doubt the prisoners would have a number; the only real question is whether the number is accurate. And frankly the profit margin on slavish labor is not really the important detail.
I don't read Chinese.