If you choose to create a Workspace, you should be aware that the Workspace owner must pay for all users in the Workspace. Billing is managed centrally with Workspaces, through the purchase of multiple licenses.
Each user that joins a Workspace needs to have their own Read license (similar to Google Workspace, Slack, Zoom). In order to add a new user to your Workspace, you will first need to have an available license for them. You can add and remove licenses by going to your Plan & Billing page and clicking on the "Add licenses" or "Remove licenses" buttons:
All licenses in a Workspace are inherently on the same plan and billing cycle. When you add a new license, you pay a prorated amount based on how far you are into your billing cycle.
After you add someone to a Workspace, and they accept the invite, they will automatically start using one of the available licenses. If you remove a user from the Workspace, the license is not automatically removed, instead it becomes available again for someone else to use. If you choose to remove an available license, you will not be charged for that license going forward (starting with your next billing cycle).