Your right. But, what stumps me is, why are ASML not charging more for these machines. Yes, they are absurdly expensive to begin with, but what would the likes of TSMC, Intel or any other fab do if ASML said they are $1 billion each? Those companies would have no choice to pay it, given how essential they are in the those companies producing chips in massive quantities, and the multiples of billions they make from it.
Every product has a sweet spot of maximum profitability on the supply / demand / price curve. The higher the price, the lower demand will be. The lower the price, the higher the demand. Important point here is that if you can't afford something, you are not part of 'demand'.
Example of this would be, say you need and can afford at most a $30,000 new car. You would like to have a Toyota Land Cruiser, which starts ~$61,000. You are not part of demand. Now, if they lowered the price of the Land Cruiser to $30,000, you would be part of demand. Along with a lot of other people.
So back to the subject at hand, with a price tag of $350M I can say that companies like UMC, GloFlo, ONSemi, and probably HP are not going to be part of demand. Demand is pretty much just going to be Intel and TSMC.
So they won't be able to sell very many of these machines.
To use your example, if they increased it to $1B each, you create a downstream issue. TSMC and Intel might buy some still - but not as many. They will have to push the cost to their customers, and as a result their customers will decrease in number, hence demand will decrease too. Then it becomes a specialty item, for example just for military or high end research, and you lose economy of scale. Instead of selling 50 over the next 5 years to Intel and TSMC, you wind up selling 2 or 3.
Manufacturers have to know if there is a market for their product, how big it is and how valuable their product is. Most of these companies have people who do nothing but study this kind of stuff. I'd bet ASML uses a consultancy since they don't come out with new stuff all the time like say Sony or Ford.