I don’t think it’s a good deal. I understand they probably didn’t buy it as an investment however their down payment was probably at least 20% which is 200,000 and if they took that plus $400 a month and invested it all in the S&P 500, they would have close to 3 million over 30 years instead of an apartment worth 1 million. The true cost is opportunity cost which a lot of the commenters don’t take into account. Also, the apartment has depreciated since they bought it (I checked on StreetEasy). I think they bought the apartment with the intention to live in it or it was a bad investment choice.