save up to 节省
This could save up to 140 litres a week.
这样每周可以节约140升水。

He said he'll spend about$ 300 on a cheap pc and then save up to buy a more expensive computer from apple.
他说他将花300美元左右买台便宜的pc，然后存钱买一台更昂贵的苹果电脑。