The militia of the Constitution was to be well organized, well armed and well trained

[Missileman]

It's evidence that the founding generation, at the time of the founding, didn't believe that the members of the militia should have to provide their own arms. If we're going to consider post ex facto evidence, which we shouldn't, we must consider all of the evidence.

It can very well be interpreted that Congress believed that every citizen should be armed in the interest of national security... even those unable to afford them.