Start reloading.
Don't wait till you run low, or out, of components to buy.
I don't "need" primers, but when Cabela's put S&B primers on sale a few weeks back, I bought a few boxes, just to put away.
Same for powder. If I see a good deal on a powder I use I get a jug, or two, of it. I've never had any "go bad" even stuff I've had over 30 years.
The next things on my list of stuff to buy and put away are pistol bullets. I don't "feel" like I have enough. Got the .223 Rem. and .308/.30-06 bullets covered last year when I saw good sales on them.