Take a look at a corporate income statement sometime,
corporate income tax obligations are NEVER included as part of "cost of goods sold".
What you WILL see is "Profit Before Income Taxes" and "Profit After Income Tax"
Corporate income tax is merely government confiscation of a portion of the profits (if any) that are earned, they are NOT a "cost" that can be "imbedded" and "passed along" to the consumer.
QED
"Taking your logic to its conclusion, there is no way that a company could ever do a budget"
"Take a look at a corporate income statement sometime,
corporate income tax obligations are NEVER included as part of 'cost of goods sold'."
As someone who has been involved in the generation of many corporate income statements, I am more than familiar with GAAP formatting.
However, the format of the income statement has absolutely nothing to do with your main point, which is that income taxes cannot be predicted. To the extent that sales and expenses can be predicted, so can taxes. I know that to be a fact, since I have been personally responsible for generating many budgets.
Had I ever left out income taxes from my budgets using your wacky logic that they cannot be predicted, I would have been uncerimonously sent back to the drawing board.
BTW, there are many legitimate costs, such as sales & marketing, research & development, and general & administrative that are separate and distinct from COGS, also. Are you going to say that those expenses cannot be predicted, either? Or is it just taxes?