That dress was an expensive mistake.

那件连衣裙看走眼买贵了。

《牛津词典》

He made an expensive mistake.

他犯的这个错误代价颇高。

youdao

It was an expensive mistake.

这是个代价高昴的错误。

youdao

As a result, some people reckon a new print edition may be an expensive mistake.

ECONOMIST: A new venture for an old paper

The problem is that acquiring Anthony, a New York native who seems to be pining to return home after seven years in the Rockies, would be an expensive mistake for the Knicks, a case of falling into the same old trap of overpaying for a big splash.

FORBES: Knicks Should Pass on Carmelo

Unfortunately, the consequence is that the trade will get away from you and that can be an extremely expensive mistake.

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