“Costs an arm and a leg”

“Fat chance”

Very little or no chance.

“An uphill battle”

A very difficult challenge.

“Fight fire with fire”

To use the same methods as your opponent.

“At all costs”

No matter what happens or how difficult it is.

“Food for thought”

Something worth thinking about.

“Fill someone’s shoes”

To take over someone’s role or responsibilities.

“For a song”

For a very low price.

“Full of beans”

Energetic and lively.