It's really confusing. He wants Reddit to pay $10 million so he isn't "loud" with API usage? He wants them to buy and takeover the app? He's wants a payment to shutdown? Is he even serious about any of this? I get the impression he lacks the confidence to ask for a $10 million acquisition, so instead he approaches the subject casually as a joke, and the entire conversation spirals into confusion due to the lack of clarity.
Either way, that's not a great deal for Reddit. They might as well charge the $20 million, and if he can't find a way to pay it then Apollo shuts down and the majority of users return to the official Reddit site/app for free. There's no benefit to paying $10 million.
The call was a failure between the two parties and likely destroyed any future negotiations. I think the best suggestion was from another user here. Only allow Reddit official subscribers to use third party apps. Reddit can charge users whatever they want, and app developers can monetize their apps however they choose.