I would be in agreement with RCC as to price. I would, however, point out that there is an unfired Darne 20 listed in the same area, with longer barrels, more choke, and less drop, at the same price.
I'll not be buying either gun. But, I know which one I would buy if I needed a 20. No offense intended, but I'd take the Frenchie.

Best,
Ted