Flash Loans - What Number Is a Million Dollars?

The person who sold that a cryptopunk to themself has now listed it for a billion dollars. It is very likely that the person was able to get, you know, more than 500 million dollars in instant loans and pay a tiny, tiny, tiny fraction of a cent in fees because of how these flash loans are constructed. Because depending on where they borrowed the money from, there isn't necessarily even a real interest rate of any kind.