Greg Mouton in Crowley supplies reeds, and so does FRM Enterprises in Canada, but FRM is mainly wholesale. Greg has Binci, Voci Armoniche, and Cagnoni. Price right now on Binci #1 is just over $300 US. Greg also supplies other materials for building.
As has been said, Salpa are no longer in production.
The reeds mentioned are popular, but if you want an accordion with that bright Salpa sound contact Randy Falcon or Andre Michot. Although they no longer make salpas there are other options.