I looked into it a few years ago & decided it was not economically realistic.
I doubt if a maker could sell 50 in 3 yrs. either in glass or plastic.
My 1st attempt at making with cast resin FAILED.
Making with Vacuum Formed Plastic or Blown/Cast Glass you'll need at least a 3 part mold. No matter which way someone goes they will still have rejects that have to recovered in cost.
db