If we make the products ourselves, we will have to carefully analyze our costs - materials, labor, and some overhead allocation. This may entail a completely separate spreadsheet. In this example, we are working on the basis of outsourcing our production requirements. This may increase our direct costs somewhat, but will allow us to keep our indirect, i.e. fixed overhead, costs down initially. Each of these categories should be broken down further as to salaries, office costs, rent, utilities, etc.
Salaries usually account for the bulk of the expenses in each category.
We might even want to show a subtotal for salaries to help us in our planning. It is relatively easy to produce estimates of expenses. These estimates are driven by our marketing mix and how aggressively we wish to build our venture. It is a good idea to do some sanity checks by consulting with peers in your industry. Also, review some statements of publicly listed companies to get additional ideas.