cost/pay an arm and a leg informal
to cost/pay a lot of money (使)花一大笔钱

we want to redecorate the living room, but I'm afraid it's going to cost us an arm and a leg.
我们想重新装修客厅,可是这恐怕要花我们一大笔钱.



ask for trouble/it:(通常用于进行时)自找麻烦,自讨苦吃,自寻烦恼 behave in a way that is likely to result in problems

They're asking for trouble, leaving young children alone in the house like that.
把小孩子独自留在家里,他们这是没事找事.

she's really asking for it the way she comes in late every day.
她每天都迟到,真是自找麻烦.