Han Jia, I think of an idiomatic phrase.

韩佳，我想起了一个成语。

This idiomatic phrase says that if you determine the price of products occur change as the quality rises or lowers. Every penny reflects a product's quality.

这句俗语说的是货物按质论价，货物价钱的贵贱随着它的质量的高低而变化，货物的每一分价值都反映它的每一分质量。