One common question we get is "how do they make all the holes in the beads?". When people make beads at home they usually use some sort of drill press and diamond drill bits and sit for a long time in front of the drill press meticulously drilling hole after hole. This method is costly, even in China. So they have developed a system that assembly lines the process.
Many of the shaped beads are cut, ground, and polished by hand and then ran through a machine that uses a sandblaster to blast a hole through the stone in a split second. Using this technique and scrap rock, chip strands can be made very inexpensively.
Some bead shapes and materials are not suitable for blasting and must be drilled by hand. This is usually reflected in the price of the beads. Many pearls are too fragile to drill any other way than by hand. It is because of the labor and difficulty in doing stone that stone beads are more expensive.
Plastic and glass are very easy to work with in comparison with stone. Hence, they are less expensive.