The variable cost should decrease proportionate to revenues, not necessarily in the absolute sense. Which means the company proves it is selling a product or service that converts disproportionate (and outperforming) to the cost of customer acquisition and cost of sales, i.e., making money at scale. For if there are no such economies of scale, there is no viable business.
I would suggest you build a financial operating plan. The sheer process of creating such a plan makes you think deeply about how all the pieces of the puzzle, the ecosystem of your company, will or are supposed to come together. The outcome may not be perfect, or even accurate upon execution, but it sure helps you tick off all your financial boxes and helps feed the dogs the dog-food, to investors who in the end care (and know) mostly about finance anyway.