Here's a reputable study that talks about the composition of...

Here's a reputable study that talks about the composition of Lupin, amongst other things.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9737668/#:~:text=Protein%20content%20of%20lupins%20is,27%2C28%2C29%5D.
They state that "Protein content of lupins is approximately 34–44% on a dry weight basis".

If we take the conservative estimate for this of 34% and assume perfect extraction and a 1-1 conversion of Lupin protein content to Buntine protein product, WOA would require 2.94 Tonne of Lupin input per Tonne of Buntine protein output.

At an input cost of $400/tonne of Lupin, that would mean a base materials cost of 2.94 * $400 = $1176 per Tonne of Buntine protein produced.
Obviously there will be operating and handling costs on top of this which I have no idea how to estimate.

At a price point of the lower estimate of $10k/tonne of Buntine protein, still seems like a likely quite healthy margin.