Why are there no 3rd party wavebird receivers?

[Shank]

I've looked around and there aren't any 3rd party receivers for wavebird controllers. I'm curious why no company or individual has studied the wireless signal and figured out how to replicate it. The receivers have become more expensive than the controllers

 

[Blargaman91]

3rd party companies made controllers with their own receivers during the life of the GameCube and, now that it's so old, it would seem weird for anyone to release a new product for the 15-year old console, even if the official receivers are costing more. You could always modify an official controller to make use of a third party receiver.