A new homebrew network adapter is currently on sale for the GameCube, called the “GCNET”. It’s essentially the same as the ETH2GC, however it connects to the front memory card port, instead of the bottom. The price is about $40 and they’re in-stock now. More info after the link:
Purchase Here: https://gcnet.neostormer.com/
Swiss: https://github.com/emukidid/swiss-gc
Original Broadband Adapter (paid affiliate link): https://ebay.us/pddXSw
If you boot GC backups via Swiss and want ethernet access, either of these adapters are a great choice and far cheaper than the original GameCube Broadband Adapter. That said, you won’t be able to load backups via RetroNAS , or use the adapter with original discs. I still think they’re both awesome projects though! If you’d like more info on the ETH2GC, please check out a video Tito from Macho Nacho Productions did highlighting it: