Animals
Food
Money
Time
Home
100

It's raining cats and (blank)

Dogs
100

"I'm going to relax and just be a couch (blank)"

Potato 

100

(blank) is money

Time

100

Wrong (blank), right time

Place

100

When one (blank) shuts, another one opens

Door

200

The early bird catches the (blank)

Worm

200

This is not my cup of (blank)

Tea

200

This cost me an arm and a (blank)

Leg

200

Even a broken (blank) is right twice a day

Clock/watch
200

The (blank) are on, but nobody is home

Lights

300

"He is the black (blank) of the family"

Sheep

300

You can't make an (blank) without breaking a few eggs 

Omelet 

300

It's worth its weight in (blank)

Gold

300

Better (blank) than never

Late

300

One's home is one's (blank)

Castle
400

Curiosity killed the (blank)

Cat

400

That was a piece of (blank)

Cake

400

"I've got $100 burning a hole in my (blank)"

Pocket

400

(blank) will freeze over first

Hell

400

Rent is going through the (blank) in this city

Roof

500

"Nobody wants to talk about the (blank) in the room"

Elephant

500

Sometimes I feel like a (blank) out of water

Fish

500

There's no such thing as a free (blank)

Lunch

500

"I see them once in a blue (blank)"

Moon

500

Home is where the (blank) is

Heart