I am not amazed at the black market. I am amazed it's so small.
It's got to be more than that, especially in high tax states like IL. Any business that takes in cash (not checks or credit cards) under-reports. They have to in order to survive.
And it's sad. Those bustin' their humps to put food on the table and a roof over their families head are told "You need to pay your fair share, i.e. More." Meanwhile others are scamming the system collecting Welfare, Section 8 Housing, WIC, Food Stamps/EBT, etc. while driving nice new car, with the latest iPhone with an all inclusive service package, while wearing the designer/latest clothes. That's why this country is doomed. The takers are outnumbering the makers.