The SEC website explicitly states: "The subscription price is set annually by Attain, LLC, using a weighted average methodology based on the number of primary feeds for subscribers at the beginning of the each year. Subscriber organizations can be invoiced annually or monthly."
There are two very detailed documents on the linked website that have both business and technical details along with specifications for the service.
"HIGHLY profitable"? Even at the highest price quoted on this thread, this looks like a rounding error --- in the sense that if you were a startup providing this information at these prices to its total addressable market, you'd have a hard time even getting funded.
The number of firms that can profit from trading off realtime access to fundamentals is not large. It's a market where viable real products need to have customer lifetime values in the many millions.
There are two very detailed documents on the linked website that have both business and technical details along with specifications for the service.
There is nothing shady going on here.