That 815 units was a proposal, not something that's actually been built. It appears the company intending to build it has since cut the proposed size to 646 units, and that's big even for NYC - the biggest on that list that's actually being constructed is 246 units and the sizes drop rapidly from there. So you'd be looking at a thousand or so NYC-sized buildings, in an area probably considerably less suited to them than NYC. (Oh, and the estimates I can find claim that apartments in that building are selling for about $2,000 per square foot. I think that's expensive even compared to SF prices. What's more, anyone who complains that SF housing development is too slow needs to realise that 246-unit building is part of a construction project originally proposed in the late 80s: https://en.wikipedia.org/wiki/Riverside_South )