what is the difference between an official design product and a cheaper licensed one, e.g. Corbusier's chair?

Question

In particular, I see his chaise longue ($2400) and "copies" ($695).

Answer 1

Lots of small details maybe different, metal gauges, the way the joints are welded, the care taken in finishing, the quality of the upholstery. Some copies are also completely different dimensions. If you are considering buying, it is helpful to see the original, study it closely. Then look at the copies and decide what you can live with. There are better and worse adaptations of the original pieces. The originals are expensive with reason, the quality of materials, construction and attention to details is usually much better. As a contract/commercial office furniture representative for twenty
plus years I can tell you that I know of no original design manufacturers, that manufacture or market copies of their original pieces. Copies and originals are not made in the
same factories.

Good luck with your inquires. You might wish to go to Herman Miller and Knoll web sites for some more information. Or to
the BIFMA ( Business and Institutional Furniture Manufacturers Association) site.

Answer 2

Price,
and people that believe that name brand is better,
Ever visit a factory? they make the same thing, and put different labels on it,