maybe not ONE of a kind but close

If you care how and by whom your stuff is made,I know I sometimes do, you want to shop at Of A Kind.

Hero_braidedcagering-product-3braided cage ring by Fortune Favors the Brave - $70 - "50 of a kind' < i.e. only 50 of these were ever made!
Hero_momentomori-product-9memento mori cuff by Bing Bang - $70-  "50 of a kind"
Hero_doublecrystalstuds-product-1double crystal studes by Better Late Then Never- $125- "25 of a kind" 
Hero_landscapetote-product-3landscape tote by Louise Goods - $175 - "22 of a kind"

The great stuff gets sold out fast but you can always visit the individual websites of most of the designers to see the other greatness they have for sale.