I see this phrase "panic buying" thrown around a lot, as if to suggest that there is something irrational - e.g. like cleaning out Costco of toilet paper - about people purchasing tubes.
I've seen tons of conversations on this on various forums and most people aren't going insane buying way more than they need. They are simply stocking up on some back up tube while they can still be purchased.
"I need this, they may not be available soon, so it's wise to think ahead and pick them up while I can."
That's not silly or just "panic buying," that just thinking ahead, being reasonable.