Taking out travel insurance may seem an unnecessary expense, but it is a must.

旅游保险费用看起来似乎是没必要的，但却是必不可少的开支。

It would've been an unnecessary expense.

这将成为一比没有必要的费用。

Don't involve yourself in unnecessary expense.

勿做不必要的花费。

Terry: I will see if I can cut down any unnecessary expense.

泰瑞：我看看还能不能削减任何不必要的费用。

Crow says he eventually convinced Mr. Jobs it was an unnecessary expense.

克劳说，自己最后说服了乔布斯，让他相信这是不必要的开销。