The price of fiber optic plate heavily depends on its geometry dimension and fiber(element) configuration.
Usually, fiber optic plate under Ø25mm (diagonal) will quite affordable. The price could range from 5-15usd depending on the configuration. And the price could be further reduced in a large quantity (e.g : 10K pcs)
However, when the dimension goes beyond Ø100mm, the price will be increased a lot. (e.g: 1,000 US dollars+)