Low? That's illegal in quite a few states in the US :D
But isn't your math: 4 people per hour, 168 hours per week, 4.3 weeks per month, $8/hour = 4 * 168 * 4.3 *8 = $23,116.80 per month? Of course, in reality isn't much higher because of FICA, payroll taxes, etc.
Even if it's only one...