Rewriting Metals [3.5, PEACH]

[Fortuna]

OK, this was directly inspired by Lordsmoothe over in the role-playing games subforum (here specifically. The idea was to give assorted mundane metals semi-magical properties, and so I decided to try to put something together. Note that this is done for the concept, and so balance issues will probably be rife, but I like fixing them.

Iron, Cold
This iron, mined deep underground, known for its effectiveness against fey creatures and magic, is forged at a lower temperature to preserve its delicate properties. Weapons made of cold iron cost twice as much to make as their normal counterparts, as does armour. Also, any magical enhancements cost an additonal 2000 gp per +1 equivalent.

Items without metal parts cannot be made from cold iron. An arrow could be made of cold iron, but a quarterstaff could not.

Whenever a person wearing cold iron armour is targetted by a spell, they gain a +2 to any save permitted and to any spell resistance that they possess, and may not voluntarily fail their save. Likewise, when they attempt to cast a spell any permitted saves or spell resistance get increased by one. This material also causes an additional 5% arcane spell failure chance.
A double weapon that has only half of it made of cold iron increases its cost by 50%.

Cold iron has 30 hit points per inch of thickness and hardness 10.

Steel
Steel is the standard material from which metal armor and weapons are made. When a creature wearing steel armor is affected by a spell, they gain a +1 to any saves or spell resistance involved. Likewise, while wearing steel armor any creatures targeted by a spell cast by you gain this bonus. Each bonus may be bypassed by succeeding on a Spellcraft check with DC of 15+twice spell level.

Steel has 30 hit points per inch of thickness and hardness 10.

Tin
Tin is a metal which, strangely, has no effect on magic at all. Tin weapons and armor cost an additional 10 gp.

Tin has hardness 5 and 30 hp/inch of thickness.

Copper
Copper is highly disruptive to magic. While wielding a copper weapon, there is a 10% chance that on any succesful hit you will dispel the most recent magic effect cast on a creature, or 50% on a critical hit.

Copper weapons deal one point of damage less than a steel weapon of that type. They cost an additional 50% of the usual price. They may not be enchantment.

Copper has hardness 5 and 30 hp/inch of thickness.

More will follow when I get up in the morning. For now, thoughts?