With more families than ever looking to stay in Manhattan instead of relocating to the suburbs, family size apartments are in demand. Despite the luxury market being glutted, prices have not substantially come down in Manhattan’s real estate market as a whole. Assuming you do not want to subject your entire financial history to the scrutiny of a co-op board, your first choice is probably going to be a condo. A quick search on streeteasy finds only nine 3 bedroom and 3 bathroom condos on the upper west under $4 mm. Between $4-5mm, you have another 11 listings to look at including a couple in newly constructed buildings.
Compare that with co-ops, there are 18 co-ops for sale under $4 million with at least 3 bdrm/3baths and another 7 offered between $4 million and $5 million.
So altogether on the Upper west side under $ 5 million you would 45 apartments to choose from which is not many.