It depends on what you mean by scrip being sold before Mass and orders being fulfilled during Mass. If these transactions are taking place in the nave of the church during the very liturgy among people who are supposed to be listening and praying the liturgy, then yes, it is completely inappropriate. If, on the other hand, people stop by a scrip cart outside the church or in a social hall to drop off orders before going into Mass and volunteers who are not attending that particular Mass are fulfilling the orders at the outside cart or in the social hall, so as to have the orders ready for pick-up once people leave the church, that may be okay.