Noun
cost performance; cost effectiveness; price-performance ratio
性能的には問題なかったんだけど、一体あたりにかかる費用があまりにも膨大で、コストパフォーマンスが悪いということでね。There was nothing wrong with their ability, it was just that the expense for each unit was so vast that the cost performance was bad. value for money; bang for one's buck
Also written コスト・パフォーマンス、コストパーフォーマンス