I live in a shelter, if you looked at the cost per person, it would probably be north 20k per resident to be housed here. This is the overhead of rent, utilities, salaries for case worker, security, maintenance, etc. When you include other parts of the system, it's easily another 5k; this isn't even taking in account of SNAP, cash assistance, medicaid, etc. There is a whole system and it ain't cheap.
Now, this isn't to say living is great. You are living in a dorm with 20+ felons, you have bedbugs to contend with, and it's dirty. I still have a normal ass job as well. Being homeless fucking sucks.