give your right arm
US /ɡɪv jʊər raɪt ɑːrm/
UK /ɡɪv jʊər raɪt ɑːrm/

1.
付出一切, 不惜一切代价
to be willing to do anything or pay any price for something you really want
:
•
I'd give my right arm to travel the world.
我愿意付出一切去环游世界。
•
She would give her right arm to get that promotion.
她愿意付出一切来获得那次晋升。