(I work at Backblaze.) We buy our drives once per month right now. This is an improvement over the early days where we were so strapped for cash we bought twice a month. :-)
We're building and deploying 17 pods this month, each pod has 45 drives, so we purchased 765 drives this month (plus replacements for failed drives that are out of warranty, etc). So if we would buy 13 months of drives all in one purchase, we might be able to go direct.
THE TRADEOFF (Gamble?) is that drive prices drop every month, so stockpiling a year worth of drives (even at a 10 percent discount) would lose us money. Before the Thailand drive crisis we had a rule of thumb that drive prices dropped 4 percent each month. But this is just a judgement call, your guess is as good as mine whether this makes sense. We're figuring this out like everybody else.
Good lord yes. Before the drive crisis we were smug and confident and everything was operating smoothly and according to plan, we just couldn't even imagine what could possibly go wrong. Yep, and we bought our drives JUST in time, the longer you delay the purchase the lower the cost the higher the profit.
What did Andy Grove say? "Only the paranoid survive." Now we run a larger buffer of drives.
It's a cool story but something just doesn't add up here.