But this is a SaaS, working with recurring revenue.

Some metrics to consider are:

- Cost of Customer Acquisition

- Lifetime Value

They could spend 200$ to get an average customer, but they will renew their subscription for an average of 5 years and generate over 2000$ in revenue during that time.

As long as you keep track of these metrics you know you're in a good direction or digging yourself a hole.

Besides other costs R&D, Admin, Marketing and Sales can be scaled up and down as needed, and become a smaller part of the costs as the company grows.