It seems like Jin and Yin showing up to literally deliver the girls out of the red broker's office means that this story will be a breath of levity in a rapidly approaching endgame. Of course, Yuma's mom being there means it will probably have some plot relevance too... I'm excited to see it bear out!
With regards to the story itself, I think what fascinates me is how eagerly the auction attendees bid on each item, but then look worried when the lights flicker and the baby-ghost starts terrorizing the place. Hama's scam spiel isn't that good, so the attendees presumably know the story behind each item giving it value—but they're still anxious about the supernatural effects on display?