There’s quite a bit that goes into the design of clothing patterns. You will almost certainly need to hire someone to develop the patterns considering this is uncharted territory. The domestic clothing manufacturers, what few are left, are not inexpensive. Overseas manufacturing will be necessary to keep the price point below $80 due to the fact that your volume will be low, even if your sales are decent. This is a niche product after all. Also, the material for the clear window that you are envisioning will become cloudy with repeated wash and wear.