What do you mean by “stay alive”? LLMs are statistical models that require a lot of number crunching in order to output a response. That’s not something you can just host without some major costs associated (Far more than any single Fediverse instance for sure, GPUs are not cheap to rent).

It’s not 135$.

Probably referring to free open-source software and not just free to download.

There is a one time purchase option. The subscription is for features that need additional cloud services.