Authenticity and Marketplace Value

Dear fellow vintage fashion enthusiasts,
I'd like to engage in a discussion regarding the words, ”attributed to,” and the market value of vintage clothing. I’d like your opinion on these two dresses.
On the left, we have a Dior dress displayed in a museum. On the right, we have an unlabeled dress being marketed by a vintage reseller as a "museum Dior dress." It has a striking resemblance to the Dior dress on display, however, it lacks the Dior tag and numbering that would authenticate its origin, and it lacks that je ne sais quoi.
It’s true that some dresses can lose their label, so it’s important to be able to rely on internal details, such as materials and construction to discern the authenticity of garments. In this case, the internal construction does not appear to possess the hallmarks of a 1950s haute couture dress from the Dior atelier.

This raises the question: What factors contribute to the marketplace value of vintage clothing? Should a dress command a significant price tag solely based on its resemblance to a recognized piece, even if there’s an absence of concrete proof of its origin? How much weight should we place on a garment's label and numbering?
I invite you all to share your thoughts, experiences, and any relevant expertise you may have.
Looking forward to hearing your perspectives.
Labels are nice (and I do really love a beautifully woven label) but I see just as much value in an unlabelled haute couture dress. It is great to have a label as it can complete the puzzle when trying to research a particular garment.