Jay - thanks for the feedback! I can definitely add a buy link to the filter readme page. We could definitely use a rewritten terms of service and clearer definitions on the site but have been distracted building.
As for the period of time question - the 18,888 covers write access to nostr.wine and 1 month of filter.nostr.wine access. We don’t have any plans to add additional payment requirements to nostr.wine but we are hesitant to make “lifetime” guarantees because we don’t know how our infrastructure will scale at 10x, 100x, or 1000x the current size.
Please do let us know if you more feedback or run in to any issues using it!