First of all, furs and vacations are not part of the underground economy. They are part of the legitimate economy. Those activities are lawful and are taxed.
Let's look at a vacationer to Disneyworld. He stays at Holiday Inn. The lodging service is taxed. Holiday Inn pays income tax. Holiday Inn's employees pay income tax. Holiday Inn provides soap. The soap manufacturer and its employees pay tax.
The vacationer goes to Disney. Disney pays income tax. Disney's employees pay income tax. Disney buys electricity to operate the rides. The utility and its employees pay income tax.
Is it really news to you that the legitimate economy gets taxed, or do you really think a vacation is an example of the underground economy. I suspect the latter. Trust me, vacations (and fur purchases) are in the above-ground economy, not the underground economy. I can't believe you disagree.
Are you trying to state that the person that earns their income from the underground economy carries the same burden today as the burden they will carry under an NRST?
True, but any currently hidden tax collected from an income tax paying customer must make up for any taxes not paid by a person avoiding income taxes such as a prostitute or drug dealer...you are not even treading water...