They could've published their documentation so it would be possible to build a client terminal yourself out of readily available parts. You'll still have to pay for the service itself, obviously. And I'm not talking about satellites themselves, only about the user equipment.
I don't think you understand the complexity of what you're suggesting. I doubt there are any off-the-shelf chips suitable to build a Starlink terminal and even if there were it would still cost over $10M and maybe more like $100M to design the terminal.
