We need to buy in bulk to reach the 'scale of economies'.
"He's throwing me under the mud." - I beleive he mean 'throwing me under the bus'.
He is the apple in my eye. (sounds painful)
I'll kick the door in on that one. (They meant kick the tires, dip my toe in the water, etc)
He was sick as a horse. (Note: Wiktionary says this is used, but I don't believe everything the internet says and I think it is supposed to be 'sick as a dog' so I added it anyway!)
