I'm not associated with them, but here's a source for Chapuis that is definitely worth looking at.

http://www.heirloomarmes.com/chapuis_pop.htm

They are advertising $9500 for a Brousse grade 470, and Chaddick's is advertising $11,700 for the same gun in the same grade.

The Jungle grade is $15K from them and $19,500 from Chaddicks!

The PH1 is the Brousse grade with upgraded wood and Chaddick's-defined engraving.

Good Luck