Here's the DM-created magic item in question:
Mask of Three Faces
When worn, the mask attaches to the wearer's face and cannot be removed by normal means. At next sundown, the mask falls off. At each time of attachment, the mask chooses a mode at random which is effect for the duration of the attachment:
Allure - +2 to Charisma, +3 Competence Bluff, +3 Competence Diplomacy
Frendliness - +2 to Wisdom, +5 Competence Sense Motive.
Madness - -2 to Wisdom, -2 to Charisma, +2 to Dexterity, +2 to Strength, and a +5 competence bonus to the following skills: Sleight of Hand, Climb, and Tumble.
About how much gold would you say this DM-created item is worth? Can you break down your analysis?