I’m not sure what you’re referring to here. Google are the file distributor for content from their store.

These rules aren’t for linking out from the store to a third party site, but rather for installing an app from the store and then linking out to a third party payment.

Yep, I misunderstood that key point here but can't edit anymore.

> The four dollars is for providing the platform that the user used to navigate to the link and download the zip file.

And does not include showing up first in search results for your app's name. That's a separate fee you'll need to pay.