value的名词是它本身：value

n.(商品)价值;(与价格相比的)值，划算程度;用途;积极作用

例句：

The ring wasn't worth very much but it had great sentimental value.

那枚戒指值不了几个钱，但却极有情感价值。

The winner will receive a prize to the value of 1 000.

获胜者将得到价值为1000英镑的奖项。

In fact, conflicts can promote individual development and thus has a positive value for development at a deep level.

实质上，它可以促进个体的发展，蕴含着深层次的发展性的积极作用。