Model scaling of AWS LZ fix costs

**Describe the Issue**
We would like to understand the cost scaling of our fix costs for running the AWS Landing zone as we onboard more customers.

**Additional Context**
The main categories of cost that could be affected are: storage (logging), networking, and security.
Increased number of projects, and/or increased usage within a project, are affecting core costs. We need to better understand how much.
Statistical model expertise might help here.

**Acceptance Criteria**

- [ ] List cost sources that are impacted by volume and scaling.
- [ ] Assess the cost of adding clients, and usage per client, up to an order of magnitude that would represent all BC gov workloads.