I started keeping a plain note on my phone back in March: date ordered, price paid, days until it landed, and whether the status said in stock or processing. Three months in, the pattern is boring but genuinely useful. My cheapest refill came from a place that quoted five to seven business days and took four. The priciest one quoted two days and took nine. Spread across four refills was about $118 for the same monthly amount, which I did not expect going in.
Stock is the part I can't predict. Two of my four orders sat at processing a full day past the estimate, and both times I'd waited until I was down to my last few days. New rule for me: order at the two-week mark, not the five-day mark.
One more thing — arrival speed and cold-pack condition don't track together at all. The fastest box was the warmest one.
Anyone else logging this stuff? Trying to figure out if that price gap is normal or just my timing.