Now that I look at it, those places are actually REALLY big (for NYC standards) so I guess the price is based on square footage and the potential possibilities of what could be done with the space as opposed to what the space actually is in its current state. Like for an extra 500k the buyers can easily fix those homes up into something really nice, and if you're spending 5+ mil on it already that's nothing.
Still... the fact that you could get a castle instead

I hate NYC, the cost of living is ridiculous and it's all just to be a speck in a sea of people.