Two Buyers, Two Sellers: A Thought Experiment On Gun Control

Imagine a pair of unlicensed private gun sellers in the same town.  Like most Americans, their state laws require no background checks when they sell a gun to a complete stranger, no questions asked.
Seller #1: A true hobbyist, he likes to try out new guns and take them to the range.  He shoots them for a while, then sells it and recoups his money so he can buy the next one he’s interested in trying out.  Let’s say *Arguendo* that on principle he never accepts more money than he paid for a gun.  He scrupulously only ever breaks even.
Seller #2:  The classic shady parking lot gun flipper.  He buys as many guns as he can get his hands on while still safely remaining under the radar.  He is absolutely “in the business”, and knows he’s breaking the law, but also knows that if his selling was ever questioned by the authorities, he can most likely escape punishment by simply challenging the prosecutor and the court to show how his activity is not simply “adding to his collection”, and then “selling from his collection.”  He knows they won’t be able to do this, so he feels safe to continue on with his lucrative high-volume gun selling ways.
Seller #1 and Seller #2 both threw a gun up onto Armslist, and both got bites right away.  And now, both sellers are pulling into their respective agreed-upon parking lots to meet their buyers.
Question:  Are the two buyers equally likely, or not equally likely, to be legally allowed to own guns?
Answer:  Equally Likely.
Conclusion:  It really doesn’t matter how you characterize the seller in some hypothetical Armslist-type parking lot meetup, since the odds that the sale will arm a dangerous criminal will be the same.  Neither the intentions, motives, moral character, or even the frequency of gun sales by the seller has any bearing on the chances of arming a dangerous criminal with such a sale.
Bottom Line:  If you think that high-volume, off-the-books gun sellers, who are in it for the money, are doing harm with their gun-selling activities, then you cannot simultaneously argue that the innocent-seeming hobbyists are somehow not doing the very same harm with theirs.