“A double-edged sword”

“On a shoestring”

With very little money.

“A dead end”

A situation with no progress or solution.

“No strings attached”

Without special conditions or obligations.

“A golden opportunity”

A very good chance to do something valuable.

“A fresh pair of eyes”

A new person who can look at something objectively.

“A fighting chance”

A reasonable possibility of success.

“Not have a leg to stand on”

To have no support for an argument.

“Night and day”

Completely different.