Hacker News Reader

It depends on how much you value the extra time and effort it takes to replace them. If you buy spares ahead of time to negate that time and effort, then have you really saved money?

View on HN

The point is that a 30% failure rate is less than the 50% discount so you only end up saving 20%, with the spares included in the purchase.

But if 20-30% failed in the first few months of an expected 5+ year life cycle, that's indicative of a >50% failure rate in the medium to long term. You'll probably come out a loser in monitor-years/dollar.

That does not necessarily follow. See the "bathtub curve".

See also "time value of money" - if you don't have to buy the spares until they fail, all that extra money is worth something to you.

There is a reason Toyota and co don't have 6months of parts on hand - and it isn't due to shortage of shelf space

Reply on news.ycombinator.com