Ann: Burgundy acquires one of last five Argyle 'hero' stones, page-13

In answer to both your posts, the attached article may assist. If you want to open a boutique store in Paris amongst some luxury names you need an initial Wow factor and that stone can provide this. So I see this stone being held till they have their own regular supply of fancy yellows, yes it's not from Ellendale but still Kimberley WA.
You stated as a mining company it is bad use of resources, but that is not what Burgundy see themselves, more becoming a diversified diamond company. I think they saw the opportunity to buy the stone fit their plan, maybe not the best timing but that stone may never come to market again! Same with the Ex Argyle staff was probably a bit early, though when else can you fit out a diamond factory in Perth with staff, cutting, laser and polishing equipment! Leave it a year and most have moved on, then you would need to source staff and equipment from overseas.
Yes some risk but shows some confidence in the Blina test work to date!

https://www.diamonds.net/News/NewsItem.aspx?ArticleID=67973&ArticleTitle=Diamond%2bMiner%2bOpens%2bParis%2bFancy-Color%2bBoutique