For those of you who don't like buying made in China products, glass seems like a great opportunity to buy local. Support your local glass blowers! Glass pieces are such works of art, why not get one made by an artisan, instead of mass produced?
Simple dildos should be very easy for even beginning glass workers to make, and someone with skill and experience could make plugs and more complicated dildos. The glass pieces from large companies tend to have few colors, both to be easy to make consistently, but also so that they'll appeal to a wide range of people. But for a glass worker, fun designs in color is probably a large part of the fun. You can get pieces with swirls of many colors in irregular organic-looking designs.
So why not ask blowers if they make toys? Even if they don't usually, they'd probably make you something to your specifications.
If you've tried researching and don't know how to find your local glass studios, maybe ask at your local head shop for the contact info of whoever blows their bongs. They'd be able to make toys or direct you to someone who already does.
And if thats too much talking to people, what about Etsy? You of course have to be much more discerning about what you get (does it have a wide enough base? do they know what they're doing? etc), but you might find something unique and beautiful, and you'd be supporting a small time artist.