The concept of user cost enables us, moreover, to give a clearer definition than that usually adopted of the short-period supply price of a unit of a firm's saleable output.

此外， 用户成本的概念使我们能够给出比通常采用的单位可销售产出的短期供应价格更清晰的定义。

It seems to have been assumed that 'supply price' has an obvious meaning as applied to a unit of the saleable output of an individual firm, and the matter has not been deemed to require discussion.

似乎已经假设“供应价格”具有明显的含义，适用于单个公司的单位可销售产出，并且该问题被认为不需要讨论。