Where do the sales come from and who gets what portion of that $60? Does Sony get a portion of that 60 if i buy it on PSN? Does Amazon? Does any other possible retailer? It isn't as simple as $60 x 4M units = 240M which therefore = profit. I don't know fully how these cuts work or what deals are at play, but I very highly doubt ND gets the full $60. Without this information determining what is the break-even point is impossible. The 20M sales might be the desired to make the return on investment positive enough for the financial risk and investment given to a project of this scale and development length. Remember in finance money has a time value attributed to it.
This is why sayings like "A dollar today is worth more then a dollar tomorrow" matter, because the faster you receive money, the faster you can use said money to get more money. That is why compound interest is a thing. If this game was in development for half a decade + then that is a lot of time where money has been thrown into a pot and expected to stew until it releases an actual product. That is quite long even for this industry, so the returns likely need to be higher for it to be deemed a success. Breaking-even is a pretty shitty result for a project that has taken an entire console generation to come out.
Well, we can calculate the time value of money. If we assume that $100 million could have achieved, let's say, a 7% annual rate of return over the 7 years of game development if it had been invested elsewhere, instead:
After 7 years, that $100 million would become $161 million. So the game would need to achieve at least $61 million of profit to make up for the lost investment yield that the $100 million would have otherwise achieved.
So, to be considered a success over a generic investment, the game needs to achieve:
$100 million budget + $61 million (investment opportunity cost) + $100 million (marketing cost equal to $100 million budget) = $261 million in sales
I still think this is well short of my $720 estimate that 20 million in sales would bring in (which is probably a conservative estimate, because I assumed only 4 million sales at the $60 price point).
As for your question, what is ND's cut? Well, did Sony also front some of the development costs since this is a Playstation exclusive? (They did something similar, for example, on Street Fighter V.) If Sony and ND shared the burden of the development costs, then they share the spoils of the sales revenue and I think the break-even point would probably be about the same.
P.S. I don't think this game is going to sell anywhere near 20 million units. My prediction, earlier in the thread, was 8 million and I stand by that. At 8 million sales, I think the game will turn a profit, but nowhere near what the expectations were for a tentpole game like this. It will be like The Rise of Skywalker, which should have made twice as much as it did.