How to configure pricing as multipliers

We are trying to use Product Configurator so that when our user chooses one or more Content options within each layer, pricing ought to multiply and not add.

For example, our base price is $6.50 if only 1 choice is selected in each of 4 layers. This is effectively $6.50 x 1 x 1 x 1 x 1 = $6.50
If someone chooses more than one choice then we are multiplying that price so if someone chooses (2, 3, 1, 1) in the 4 layers then our price would be: $6.50 x 2 x 3 x 1 x 1 = $39.00.

We have the base plug-in and also have: Extra Price, Save Your Design, Multiple Choice, Conditional Logic and Form and Text Fields.