I got mine from CDNN Sports along with couple of handgun magazines, spare barrel, and 20ga Remington Baikal choke tubes for my King Ferry Ithaca 37 20ga. CDNN has expensive shipping handling, therefore one must bundle to make order worthwhile. The prices for different bore snakes range from $3 to $12. I don't want to guess what something with name Sage&Braker might cost, I hope at least it's made in USA or EU not China or India.
The BSS sidelicks were never cheap. I remember LNIB sample in late 1980s would fetch almost $3000.