The BattlerGC Pro might be the GameCube controller’s final form
Retro Fighters’ BattlerGC is for the modern Smash player.
Sold out
The preorders haven't started yet, which I guess they just implemented by setting the stock to 0. Preorders open at the 1st of May at 9:00AM PST according to the product page.
Ah, thanks for the clarification