If you’re looking for a new home and would like to avoid paying the "mansion" tax that kicks in on purchases of $1 mil and up, take extra careful notes on this selection of sales listings across Manhattan, Brooklyn, Queens, the Bronx and Staten Island.

You might also take a moment to boost your buyer IQ with BrickUnderground’s How to Buy Guide. New to NYC? Take our crash course on how to find an apartment in NYC. And be sure to do a background check on the building before you make an offer with the in-depth property reports available on Point2 Homes, a BrickUnderground sponsor.

7 questions to ask about the building before you buy an apartment there [sponsored]

How to buy an apartment that's not for sale using PropertyShark.com [sponsored]

Top 12 questions New Yorkers ask their mortgage bankers [sponsored]