The listing describes this building as being in Mott Haven, but it is a bit North of 149th and Westchester Avenue, so I am not sure I'd call it Mott Haven (Melrose? Morrisania?).
This is a run of the mill butt fugly Fedders building, but you'd be able to grab a residence and two rental properties for $650K. Not sure that this is the market to take on rental properties, but maybe it could be the time to scrap together whatever you can and get in the game.
If you could beg , borrow, or steal the 20%, which is $130K, the monthly mortgage would be around $3,100. Now $130 K is hard to come by; your author would have to hit the lotto or inherit an Italian soccer team from a long lost uncle. But if you did have some munificent uncle and and somehow came up with the cashish, you'd be able to rent the 2 bedroom for $1,000 and the first 3 bedroom for $1500 at a minimum. That means you'd get a 3 bedroom apartment for about $600/month AND the tax benefits of the mortgage interest AND the equity that would be slowly built.
It would be a gamble (and we've all learned the last few months that real estate gambling is not risky at all, especially if you take out an exotic mortgage, right?), but sometimes you have to take a shot.
On a practical level there's a train right down the block. The 2/5 train stops at Jackson and Westchester Avenues. There's also parking: a one car garage and a two garage driveway.