Unless you upgraded the style of the slave after you took the screen, that's probably the reason he's not buying her. It's on red in the screenshot, you'll need to get it to A. Salon trip is usually enough. Also, once you offer her with low style to him, he probably won't buy her even if you increase it.
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My questions:
Do you need to do something specific to get your brand status to legendary, or is it just a grind? I know the required point number doubles with a lot of the other stuff, so I'm leaning towards the latter, but I've sold a ton of slaves since hitting A on it and I'm still on A. Do the quality of the slaves you sell affect how much brand status you gain? I've been mostly selling B+ slaves to clients and guild auction.
Guild auctions raise your Guild Reputation too, no? It hasn't been raising either.
Just checking so I'm not grinding in vain.