>Furthermore, their pricing plan is insanely cheap, they even upped usage limit for their cheapest plan, lite plan, which is at 5$ / month.

Unless something changed their plans aren't really worth getting. They're not that much cheaper than the per-token rates, and because it's a plan, you have to contend with weird usage restrictions. You're better off paying per-token unless you have some use case that demands a very steady stream of tokens.