Those are what I was alluding to when I said "it wouldn't be the first time the Feds abused the ever-loving hell out of the Commerce Clause" :)

Both those cases entailed the defendants manufacturing something, which would be where the Feds would claim jurisdiction via their jurisdiction over interstate commerce. It's harder to make that argument w.r.t. something after a retail sale has already concluded (i.e. after the interstate commerce has happened). I wouldn't doubt the Feds would try to assert that literally everything that ever happens is or pertains to "interstate commerce", but that'd be sufficiently broad as to invalidate all sorts of other judicial precedents if actually held up in court.