I agree that guns are usually available anytime (not sure you can get much better prices at gun shows than you can online from gunbroker, Buds, summitgunbroker, etc. That said, sometimes a really incredible price presents itself.
Of course, the blades are a limited time thing, although they usually show up on the forums--sometimes for cost or below--the occasional knife show, and/or ganzas.
Are there gaping holes you are trying to fill in your guns or knives? Focus on that first.
The problem here is it looks like we'll be having far too many releases right away. I can see it will be really easy to get carried away.