Motorized screens have complex designs in order to keep the screen flat after many up-down cycles. Their mechanics (motors, guides, tension wires, etc) have to be robust so they don't fail after a few months. The good ones are designed to work for years with multiple daily uses and only minimal maintenance. A perforated screen (which provides the acoustic transparency) is also more difficult to make than a solid screen.
If you don't mind ripples in the screen's surface, you might want to consider a manual pull-up screen instead. They're quite a bit less expensive. To let audio through, they usually have perforations in the black section which is below the non-perforated screen area.