Is it possible to buy something at the market?

It asks for login to a Cloud and offers no registration.

Looks like selling something is not on RC team plans :)))
I tried to ask the support about how to register and it looks they do not bother to even read letters.
Just robo-like answers about weather and pricing plans.
And I’ve never seen support answering like this:

You can reach out to our support team in [support@rocket.chat](mailto:support@rocket.chat).

They will be able to help you.