From story:

- Lease a 4 bed apartment, get better rates by paying full year of rent in advance (not easy for most people).

- Sublet the 3 remaining rooms at near market rate.

- Accept the risk of default and/or not finding tenants.

What you really get for 350$ is a single room in a big apartment. Still a good deal, but there are substantial risks and lots of upfront investment. Like picking up nickels in front of a bulldozer, it'll work out for the better... most of the time.