As a complete economist noob this is my understanding: When discussing huge investements, the cost of goods and services does not really matter, but what matters is that what is the expected profit margin from the investment and at what risk.

From this point of view dollars do equal the estimated size, not how much commodities or services you can buy with it.

Someone with more experience can comment hopefully on this.

You want money in nominal terms, so PPP doesn't matter. EU is not really a single market, they have unified regulations, which is helpful, but at the very least language differences mean you're doing custom work for every country.

> EU is not really a single market, they have unified regulations, which is helpful

The EU doesn't really have unified regulations. I mean, regulations passed at the EU level are unified, but countries have a great degree of country-specific regulations themselves.

Now, technically states within the US have the ability to regulate things at the state level, but due to various aspects of Constitutional law (the Commerce Clause, and case law such as the Sherman Antitrust Act, etc.), there are far fewer state-specific regulations that companies have to worry about for interstate commerce within the US than international commerce within the EU. Unless you're dealing with very specific regulated industries (money transmission, health insurance, etc.), you generally don't have to worry about a lot for basic interstate commerce in the US.

Yes, if you want the most money, you want the highest nominal number.

Something to consider as well, is there is fairly wide spread consensus that China's GDP is significantly artificially inflated.