Create a new calculation named truePrice as:
[Price] + (abs([ChargeType] == 'INJ')?3.89:0) + (abs([ChargeType] == 'DISP')?7:0)
you will also need to edit the Total Price calculation from:
[Price] * [Quantity]
to:
([Price] + (abs([ChargeType] == 'INJ')?3.89:0) + (abs([ChargeType] == 'DISP')?7:0)) * [Quantity]
In the cart display page, you will want to replace the Price Display to use the truePrice instead, you can do this using the bindings panel. and in the Checkout code, you will need to edit the checkout behavior to pass the true price instead price to the gateway.
