The H1B visa requires a minimum pay as it is right now. However, what some companies do when they sponsor a foreign worker for H1B is to hire the person part time on paper and thus being able to pay a lower wage, but still in practice requiring him or her to work full time. This is an anecdote I heard but I know it occurs. For many people, having the chance to come to the U.S. is like winning the lottery, and they will not report their employer.