bracelet
釧 centers on a circular ornament worn on the arm: a bracelet. The meaning is specific and concrete, with no major abstract extensions.
釧 combines 金 (metal) with 川, which likely contributes the sound. The character originally referred to a metal bracelet or armlet.
The left side is metal 金, and the right side is a river 川. Picture a metal bracelet shaped like a winding river around your wrist.
For セン, imagine a shiny metal bracelet costing one thousand 千 (せん) yen: 千 -> セン, and the metal 金 bracelet is worth exactly that.