‘A dime a dozen’
The common phrase “a dime a dozen” actually originated in reference to eggs. A popular marketing gimmick in the 1800s was to price food and drink items so that one could boast that customers only needed a dime for it.
Eggs, which are typically sold by the dozens, were priced as such back then, although they’ve changed quite a lot in the decades since and were probably much more expensive the year you were born.
Saying something is “a dime a dozen” means it is very common, and therefore, not very expensive or noteworthy.
It’s mainly used in the United States, making it a regional slang term that others might not understand.
