Binding Charm is not working

masterlike

Hi guys,
i have been trying to bound my defensive weapon Twilight Melody with a binding charm but doesnt let me, it says: "Insufficient Funds" i have bought already 2 Binding Charm and nothing (i thought maybe binding charm thing has changed and now we need two item for weapon?) unfortunally same error.
If you could help me please so i can use my orbs that are for bound items i would appreciate it,
best regards
Drey