Echar la soga tras el caldero

Echar la soga tras el caldero
 

Hola:
¿Que quiere decir este modismo?:

Echar la soga trás el caldero?

From what I can tell it means to lose something important

It means "Throw away the main item after losing an accessory." (Dejar pedir lo accesorio, perdido ya lo principal.)
It's akin to the saying, "Throw good money after bad."
Another possible match: "Throw the baby out with the bath (water)."