Stingray is a food fish in much of SE Asia. I'm not sure when they began to realize in SE Asia that there was a market for the prepared skins (Shagreen). But Shagreen has been around for quite a long time now. The main thing that previously made it completely unaffordable was the very labor intensive (and thus high cost) of preparing the skins. And the high cost of then fabricating them.
Now that the basic preparation of the skins is being done in SE Asia the cost of the raw product has dropped substantially. And you will find web sites selling 'sting ray' products for prices that were previously so low they were previously impossible to achieve. (Wallets, belts, etc. etc.) These items are also manufactured in SE Asia where the labor are costs are low.
But, as DWFII said - the material is very hard to work with and there will always be a premium associated with it - especially for complicated items such as shoes.
There are some makers who are making items such as decorative boxes, furniture inlays, etc. etc. with some commercial success. As in these cases the skin is simply adhered to a subsurface and no sewing is required. Again making the fabrication costs bearable.
In any case - the real demand for removing the stingray from the water at the moment is FOOD. The skins are of secondary importance.
