What do you mean by "make profit from that cup of coffee"? A cup of coffee is hot bean water in a cup - is profit simply the price Starbucks charges minus the cost of (water + bean + cup)? What about the cost of energy to heat the water? What about the fractional cost of the machine that actually puts the water and beans together to brew the coffee (you could do some sort of analysis based on purchase price / total number of coffees made over useful lifetime)? What about the small fraction of time the barista spends making and handing the coffee to you? What about the wear and tear on the machine (e.g. it breaks down X% of the time and costs $Y on average to fix) - does that factor into this "profit" you keep talking about? What about the rent on the building? If none of that matters, then you should spin up a competitor where you simply stand on a street corner hand your customers a cup, cold water, and some raw beans - I don't think you'll take too many of Starbucks customers.

All of these factors, and many more play into the "profit" of an operation like Starbucks, so how do you determine what the real true profit of that one cup of coffee is? It is much simpler to simply say "Hey, just hand over x% of profits at the end of the year" with some reasonable guidelines as to how accounting should be done (see stuff like GAP for example) than to sit down and determine what the individual "profit" is for every single individual cup of coffee sold at every single Starbucks location.

>Otherwise you could simply: Buy expensive stuff -> even out with profits, buy expensive stuff again, even out with profits and never pay taxes.

Yep, you could do this. Only problem is, uh, you never make any money. If you're running a hobby or something, that's fine, but most people owning business want to realize some profit...

If course there are still shenanigans you can pull between different tax districts, but someone somewhere needs to realize a profit at some point - otherwise they are running a jobs program and not a business.