a dime a dozen

baker's dozen

Thirteen; a group of thirteen.

baker's half dozen

Seven, a group of seven.

banker's dozen

Eleven.

cheaper by the dozen

Handled more efficiently as a group, rather than individually.

decimal dozen

Ten, a group of ten.

drop a dime

To make a telephone call.

nickel and dime

Small time; operating on a small scale; involving small amounts of money; petty or cheap.

not worth a dime

Worthless or nearly so: lacking in value.