Food
It's a piece of cake
Easy
Under the weather
Sick
Break a leg
Good luck
Time is money
To work quickly
A bird in the hand is worth two in the bush
What you have is worth more than what you might have later
You can't have your cake and eat it too
You can't have everything
A perfect storm
the worst possible situation
Pull someone's leg
To joke with someone
A dime a dozen
Something common
Birds of a feather flock together
People who are alike are often friends (usually used negatively)
Cut the mustard
To do a good job
Every cloud has a silver lining
Good things come after bad things
Wrap your head around something
To understand something complicated
Spend money like water
To spend money freely as if it were in endless supply
Don't count your chickens before they hatch
Don't count on something good happening until it's happened.
Eat crow
To have to admit that you made a mistake
Saving for a rainy day
Saving money for later
Costs an arm and a leg
Very expensive
All that glitter is not gold
All thing are not as good as they look
Go on a wild goose chase
To do something pointless
You can't make an omelet without breaking some eggs
There's always a cost to doing something
A storm in a teacup
A big fuss about a small problem
Hit the nail on the head
To get something exactly right
As sound as a dollar
Very secure and dependable
Kill two birds with one stone
Get two things done with a single action