Why is it that the disarmists believe they can toy with the Second Amendment while all others are sacred? What part of "shall not be infringed" don't they understand?
A better analogy is asking what the upper limit on ownership of Beanie Babies is. Or Cabbage Patch Kids, Legos or Star Wars action figures. Or Pet Rocks (which can be used as weapons).
However, to repeat what was said above the title of the article is wrong. The author is talking about the point of market saturation, and doing so from a pro-gun ownership perspective.