You know that saying "caveat emptor." So, you should be caveat emptoring all over the place with this Fair Page Rates site.
Even though the site states
"The information presented here has been gathered and researched by professionals from across the industry,"
there is no way for you and me to verify that. The respondents are anonymous. So, anyone -- a pro, an amateur, a hack, a publisher, a ne'er-do-well -- can say what they want. There is also a note that some of the sources are from what comic book industry professionals have said at panels.
The Fair Page Rates site will tell you (thru its unvetted sources) how much page rates are for work-for-hire artists and writers.
I'll admit that it's an interesting read, but since the respondents are anonymous -- you have to take it on faith that they are telling you the truth when they cite figures like:
How much are comic book artists paid per page?
How much are comic book writers paid per page?
How much does DC, Marvel or another comic book company pay for cover art?
There is also a section where these anonymous creatives complain about companies specifically.
If comic book pros want to go on the record, via their official social media sites, I would trust that what they are saying is right. But this way of gathering information is open to ANYONE who has access to a computer. How can it be accurate?