What does the idiom in this text suggest?
Cell phones once cost an arm and a leg, but today the majority of people can afford them.

 - Cell phones were once very expensive.
 - Cell phones once varied greatly in price.
The text uses an idiom, an expression that cannot be understood literally.
The idiom an arm and a leg suggests that cell phones were once very expensive. A part of your body would be a high price to pay, so the idiom means that something is very expensive.