[mousquet]

Well, panoramic views from up there will be unique and there'll be all amenities you get in ultra luxury hotels. So it's much the same kind of stuff as what you get in Manhattan's billionaires row.

Maybe some if not most wealthy people will still like their mansions or large apartments in central Paris better. Maybe some apartments in those towers will be purchased as mere speculative products, as is the case sometimes in New York. But these will clearly be a hit anyway, simply because there's nothing like that over the metro area yet.

Moreover, again, the towers are actually neighboring Neuilly-sur-Seine, a suburban town full of rich people just across the river.
The developer knows where he is. He wouldn't build such a luxury thing that might cost up to €3 billion anywhere.

Hopefully, we know how much penthouses sell, just out of curiosity. Although I doubt the developer and purchasers would boast about it.