It should be percentage points, because "100% cheaper" would already be free.

It probably means AWS is 440% more expensive.

Technically yes but no person is reading that and thinking backblaze is paying you or its free. Its a nitpick

I have always found that phrasing to be confusing. Consider the reciprocal, “half as cheap”. Should that be interpreted as… double?

Say “half the cost” or “cheaper by half”.

> Consider the reciprocal, “half as cheap”. Should that be interpreted as… double?

If the phrasing makes it clear they're talking about a higher price, then yes that's a good interpretation. You get half as good a deal.

Someone might say "half as cheap" to talk about a price drop by 50%, even though that's not really correct, but such is language.

What is 440% less than 1, then? In my book, it's -3.4.

I've considered it, and decided that "twice as cheap" is equally poor choice of words

It doesn't make sense. Consider the phrase "once as cheap". Multiply by two. That's twice as cheap. Meaningless.

Do you think "twice as expensive" is meaningless? Because by that same logic, if I start with "once as expensive" that's not a number and multiplying by two gives me a meaningless concept.

Once as expensive is a number, it's 1 x the cost. Twice as expensive is 2x the cost. Once as cheap might arguably be 1x the cost, but twice as cheap is undefined.

> Once as expensive is a number, it's 1 x the cost.

Nobody says that. If someone said "once as expensive" I'd interpret "once" as talking about time.

"Once" can be a counter but not a multiple.

It seems like we're taking at cross purposes. I'm not trying to convince you that anyone says "once as X". I'm just saying "twice as cheap" is nonsensical. Because it's a multiple of something undefined.