A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Date: 2017 Aug 30, 07:52 -0700
Go to eBay.com and search. I had better luck with "Plath sextant". There are not many for sale at any one time.
In the upper left corner click on "refine", then "more", and then "sold items". It will automatically change the search and show a goodly number of sales.
I see prices from U.S. $200 for a corroded one to over $2000 for a WWII one. C. Plath is one of the more expensive sextants without being an antique. As such there are some fakes offered - search on sextantbook.com.