Kinda reminds me of something I learned in elem school. A single pencil costs $47,000 to make. The subsequent pencils costs <$.01 to manufacture once you bought all the lumbar, graphite, paint, machinery, and then put it all together.
This piece is probably something like that. It costed Apple $MM to develop, but so few are sold that the avg cost per dongle is somewhere around $300.
With that said, you’d think Apple would be willing to take the loss on this device if it helps developers create better apps which therefore makes the AVP that much more valuable and appealing.