I'm working in the infant stages of a SaaS platform and we're working on estimating cost. Right now our hosting and bandwidth expenditures are relatively low as we have only one customer, but we need to be able to estimate hosting/bandwidth costs up to a relatively large amount of customers.
What is our best bet for tackling this? Are there worksheets/calculators around where we can plug in the average request size per user, average number of requests per session, average number of sessions per day (we have these metrics already for our first customers) and work on expanding it that way? We need to rationalize to our investors the need for "pay ahead investment" for SaaS with real numbers, and the hosting/bandwidth side of things has us scratching our heads.
This is a new road for many of us, and I'm hoping someone in the community may be aware of best practices in estimating these sorts of things.
Thanks for your help!