Are you allowed to make Bots "paid"?

I seen a Bot (called Clan Labs), but you have to pay montly (no lifetime), which I don't really think is allowed...? Maybe tell the company to make it free, and make it paid for premium features like Unbelievaboat has, so that everyone can get it. TL;DR: The bot in question is Clan Labs, which is paid monthly which I think is unfair tbh.