You can set a minimum charge as well as a quantity break on a total meter.
There are three methods of count on the Total Meter
If you set a meter price product to the total meter, sum the counts from each of the children meters x price ex on the total meter as well as charge the individual copy counts for each child meter.
If you set a qty break on a total meter and a minimum charge on the total meter, on the meter charge run, charge the minimum as well as summing the copy count for each child meter x price on the total meter + each individual copy count charge
Click on New
See screen shot of example below