Sure, there may be somebody at a gun show who wants to buy cheap guns for resale to criminals. But they ll pass the background check anyway unless they happen to be a convicted felon. And even if you thwart that tiny number of criminals from buying guns at gun shows, it certainly doesn't preclude them from buying guns somewhere else. If a criminal wants a gun, no law written will prevent him from getting one. Virtually all gun laws have the same flaws because all start out with that false premise.
More gun laws equals less crime or less violence.
It's simply not true. And then, after all, there is the pesky little Second Amendment problem. Our Constitution, debatable and up for interpretation as it is, quite clearly prohibits anything as drastic as gun confiscation. We have to do something. Frankly, I'll bet alcohol kills more people and destroys more lives than guns in any given year.