Living in sky scrapers sucks and is not enjoyable. Same with living in suburbia. The sweet spot is densely packed urban areas that are built on the human scale.
what modern skyscapers are doing wrong is putting in only large-footprint high-end retail (like department stores) on the street level, or nothing at all. A zoning change to require small retail stalls at the street level would go a long way to making cities more livable. And all those people living upstairs generate a lot of foot traffic to help all sorts of businesses thrive. (what I'm talking about overall is what makes midtown NY so unpleasant compared to other NYC neighborhoods)
...is not mandating proper insulation/noise-proofing.
Near the subway, and surrounded by historical buildings and nice architecture ... where an apartment usually costs an exorbitant price.
It's not that it's very expensive to build (well, it's not cheap either), it's that there's so little supply and so much demand.