Why do some Manhattan buildings have so few units for sale?

I always find it interesting to see that in some Manhattan buildings that are very few apartments for sale. In 400 Central Park west, a 414 unit condominium there are 6 apartments for sale, and 2 of those are in contract. So out of 414 units, there are 4 units available for sale or less than 1% of the building.

Contrast that with 120 Riverside boulevard, which has 23 units for sale with only 2 of those in contract. The 14 year old building has 276 units and many amenities. But taxes for a 1292 sqft 2bd/2ba run around $21,000 per year. Perhaps, this is the clearest example of the effect of the Tax Reform? Either way, with nearly 8% of the building for sale, it might create a pause in a buyer looking to purchase.

The Author-  Brian Silvestry , a licensed real estate broker, has been selling residential and commercial real estate since 1999. He has sold in every neighborhood from Battery Park City to Washington Heights.