1. Minimum wage is above $5.
2. Anybody below 10,200 (last check) is below povery level and would qualify for government assistance in the form of discount housing, welfare, food stamps, and other programs (including utility subsidies and even free cell phones).
3. Cost of living is significant to determining "wealth". A 500 sq. ft in Dallas can run you about $430 a month, but in New York City you're looking at about $1200. A man making $30k in Dallas would be much better off financially than a man making $30k in New York City.
4. A person making $9100 a year would get almost all of their tax contribution back (SS and FICA excepted).