cost-effective
adjective uk/ˌkɒst.ɪˈfek.tɪv/ us/ˌkɑːst.ɪˈfek.tɪv/
有成本效益的;物有所值的;合算的，划算的
If an activity is cost-effective, it is good value for the amount of money paid.
It wouldn't be cost-effective to buy an expensive new computer when all you want to do is store your photos. 只为保存照片而买一台昂贵的新电脑并不划算。