It’s going to vary based on the usage amount. Popular apps are going to be charged a lot.
From Reddit’s blog about the change:
Effective July 1, 2023, the rate for third-party apps that require higher usage limits is $0.24 per 1K API calls.
Apollo’s developer stated in May 2023, Apollo made 7 billion requests, which would put it at about 1.7 million dollars per month, or 20 million US dollars per year.
My go to solution.