Essentially; primary difference being the moa trigger on the BACO version.
They didn’t make a ton of the BACO stainless supergrades so that price doesn’t surprise.
And - point of trivia - there were no classic stainless supergrades made outside of the custom shop until the very end of the classic run, and those were the 7 digit wsm’s.
And before somebody jumps on me about the 358 STA - it was essentially a stainless supergrade just not marked as such!