I am working with glass rods from Murano. You think you need to buy it in Murano. Yes, it is possible, but it is profitable if you buy a huge quantity, more hundred kg.
I buy myself the glass rods not in Murano. There is many small shop, where you can buy rods in a small quantity.
I can offer you the following shops.
Germany: Otterbein Glass
Netherlands: Artyco Object
Swiss: Crea-Arte GmbH