Universities/Athletics - with Multiple Teams

Hello! New to Airtable and wanting help with appropriate structure.

We have Renewal Clients with the opportunity to up-sell each client. basics stuff here,
but we are wanting to calculate based on a 90 day upsell window when a certain stage is triggered Open. So we are wanting to create multiple views with dependent tasks associated with each stage along with triggers.

Gantt View seems to be the answer but need help structuring the tables, see below.

Renewal Client X - Renewal Deadline Date - Renewing ARR - Projected Upsell ARR - stages (Internal Strategy (Open), Client Success Annual Review, etc…)

Each client has a maximum value or baseline price, and the rate at which they are paying. If they are below rate - we are projecting the upside to be the new ARR.

So need a way to calculate what they are paying, what they should pay.

We have different pricing structures based on conferences, sport. How should we setup the above in order to create scale for each new renewal that we add to this example above?