A dime is a small amount of money. A dozen is 12 items.
When something or someone is described as being a dime a dozen it literally means that you can get lots of them for a small amount of money. - ie There are plenty more like them about. (the person or item is not unique.)
How does this make me feel?
How does one handle this statement, because it does seem to be true.
If I'm going to make games, I'd have make unique ones.