Correct

一本万利

/ yī běn wàn lì / 
Strokes

Definition

small capital, huge profit (idiom); to put in a little and get a lot out

Example

Definition

a small investment brings a ten thousand-fold profit—make big profits with a small investment

1
Zhè
这
shì
是
yīběnwànlì
一本万利
de
的
shìqing
事情
  
,
hélèérbùwéi
何乐而不为
  
?

This is a highly profitable undertaking. Why not go ahead with it?