Roles and permissions
The four roles, and the difference between a role and an action.
The four roles
Owner. The principal. Connects accounts, adds people, sees everything including cost and margin. There is normally one.
Admin. Manages users and settings. Notably, an admin does not bypass per-user data visibility: they can add a member without being able to read that member's private rows. Managing people and seeing their data are separate powers.
Member. A person in the business. Sees their own work and whatever is shared with them.
Web only. A limited tier for people who sign in to the dashboard but do not get a chat channel.
Roles versus actions
The role is coarse. On top of it sits a catalogue of granular actions an admin toggles per person: reading mail, writing invoices, driving the browser, seeing inventory costs, and so on.
This is the control you will actually use. Two members with the same role can have very different capabilities.
Capability and permission are different things
An action can be permitted and still unavailable. If the instance has no mail connector, nobody can read mail regardless of their permissions, and Suvi hides the tools rather than failing when asked.
Cost visibility
Who can see acquisition cost, supplier and margin is its own setting, separate from inventory access. A member can be able to sell from stock without being able to see what it cost.
Seats
Your plan carries a seat cap. Admins cannot raise it from inside the product.