Some hills are worth dying on ~ some aren't. This one doesn't seem to be worth it.
I disagree with you here; the State's own Constitution specifically prohibits a municipality (ore county) from regulating "in any way" the right to keep and bear arms -- and the annotated constitution shows a good precedent for including sales in that 'regulation'.
The reason that this is important is because if the Constitution is so ignored it ceases to have any meaning whatsoever; see the federal government and the US Constitution for an example of this (esp. WRT the 4th, 5th, & 2nd).