EDIT: I’ve just done some quick research and it seems like stellarsan is a locally made equivalent to starsan in Australia. It’s probably so much cheaper just because it’s not an import.

Starsan is a recognizable trusted brand. I know exactly what I’m getting when I buy starsan. I have never before heard of stellarsan and cannot vouch for how well it works. I will say that the fact they’ve specifically chosen a name that could feasibly be confused with the established brand does not bode well for their own legitimacy.

That’s the reason for the price difference I would guess. Name recognition vs taking a gamble on some unknown brand

If you must buy online because you don’t have a local homebrew store, I recommend only doing so through a reputable seller that specializes in brewing supplies. Amazon is not ideal, and I’m not sure if kegland can be trusted as I’ve never heard of them. Try to make connections with other brewers in your area and see where they are ordering things from. Sadly, from what I’ve heard Australia is not the easiest place to source…well, anything from lol