Please take a few minutes and think about how it doesn't make sense to talk about something having *less* of some property (cost, temperature, speed) as being some positive multiple of said property with regards to whatever it's being compared to.
"A is 10 times slower than B" No. Speed is a measurable phenomenon. "Slowness" is not.
"A is 10 times thinner than B" No. Thickness is what is measured. "Thinness" was invented by marketers.
"A is 10 times colder than B" No. A's temperature is 1/10th B's temperature.