At least, I understood it in some other way.

With some "back of the envelope" calculations (using Reddit provided revenue and user number) Reddit's revenue (not earnings) / user month is $0.12 , around $1.4 user/year

In the case of Apollo, the "intended" revenue per Apollo user would be $2.5 per user month, around $30 user /year

From the body of the post, search for the following header: Why do you say Reddit's pricing is "too high"? By what metric?

The $20 Million is what would cost to continue using the API with the intended price point.

Also, $500.000 year would be revenue, not earnings. As I understood, he's not a "solo" developer working in his basement. There's people and infraestructure to pay from that number (I don't know neither how many people nor how much costs "keeping the lights on", but anyway, I don't think those numbers are relevant)

My own opinion: Let's say Reddit's break even point is around the Apollo's intended cost / user. That would mean that with a revenue of $0.12 per month * user, Reddit would be losing around $800 million / month. That's close to $10.000 million / year. Even as a ballpark figure, I find it suspicious to say the least.

BTW: I've never used Apollo. RIF user from long long before they had to change the App name