Why do you need to know these percentages? As your sales increases or decreases, your material cost, labor cost, and variable expenses will track accordingly. They will track very close to the same % as your current business. As an example, let's say your current sales is averaging 贄ꯠ per month and your material cost is averaging ฤꯠ per month. That's 20% of your sales (ฤꯠ ÷ 贄ꯠ = 20%). So, what would your material cost be if your sales were averaging 赨ꯠ per month? It would still be 20% but it would be 20% of 赨ꯠ or ุꯠ. So with these percentages, you can project your material, labor and variable expenses. See how it works?
If you need to get going quickly to ride the wave of a fad before it fizzles, then fast, bare_bones planning may be all you've got time to execute. This works best when you've already got the infrastructure in place, perhaps from previous projects or an established business, and you can simply shift energy and resources to the new idea.