Data envelopment analysis (DEA) technique is commonly utilized for efficiency assessment in a variety of fields for both theoretical and applicational purposes. In classic cost efficiency measurement models, the input and output data and input prices should be known for each decision-making unit (DMU). However, in real-life markets the input prices are not precisely defined for DMUs. In this paper, we shed light on the fact that fixed prices assumption cannot reflect the reality of situations, because market will force lower prices if greater amounts of a product are purchased. It can be said that discounts are automatically considered in these circumstances. To this end, an innovative idea is considered to modify the classic cost efficiency DEA model in order to investigate the situations of real-life markets. Then, by an empirical example, a comparison between the proposed approach and the classic cost efficiency model is provided.

出于理论和应用目的，数据包络分析（DEA）技术通常在各个领域用于效率评估。在经典的成本效率度量模型中，应为每个决策单位（DMU）知道输入和输出数据以及输入价格。但是，在现实生活市场中，DMU的投入价格并未精确定义。在本文中，我们阐明了一个事实，即固定价格假设不能反映实际情况，因为如果购买更多数量的产品，市场将迫使较低的价格。可以说，在这种情况下会自动考虑折扣。为此，为了研究现实市场的情况，考虑了一个创新的想法来修改经典的成本效率DEA模型。然后，通过一个经验例子