I've several question about collector items
1)how many are there?
2)what item that has the highest value and the lowest value? and why they are the highest/lowest?

I'm not positive how many are there.

Hampa Knife, Siku Master Piano, Hector Relax, and others are just some I can think of off the top of my head.

IIRC: Hector Relax is the most expensive one. Why? Because there's the least in existence, and it's purchase price is insane. Use to be worth a hell of a lot more, but it's dropped appreciably in value.


Collector items hold no function, but definitely a good marketing tool.

Haven't counted. Also depends how you classify collector items.
List of buyable ones here.
List of collector items and owners. Bit outdated.
Some items like Ishi's Ishi item and other things like beta hairs and other weird and wonderful things aren't there though.

Highest value and lowest value just depends on what someone is willing to pay. Hector relax item is the highest value buyable in the shop due to it's rarity and high $ cost.

Why this is a collector item?
http://forum.toribash.com/tori_shop_item.php?id=617

and what the reason that collector item made?