It's just money down the drain, you know.

你要知道，这是白白丢钱。

《牛津词典》

To study English with Xindongfang is just pouring money down the drain.

跟新东方学英语就是把钱打水漂。

youdao

The mobile telephone is too old, paying to fix only lets you pour money down the drain.

这个手机太旧了，花钱修只会使你把钱付诸流水。

youdao

Without sound property rights, the billions of dollars sent to save Africa will be money down the drain.

FORBES: Africa and economics

Given that the government pays an average of 10.4% to borrow, its investment in the banks is money down the drain.

ECONOMIST: Indian banking

"These products are often referred to as upgraded accounts, but if you end up paying for an element you cannot claim on, it is money down the drain, " said Sheila Nicoll, FSA director of policy.

BBC: Bank rules seek to prevent account mis-selling