Material Sciences in Into the Heart of the Dragon

My Into the Heart of the Dragon campaign has a house rule where you can add tags to items that make them worth +50% price per added tag rather than a flat 50 gold. Some items are of a lower quality, and have modifications that make them cheaper rather than more expensive. This reduction is also -50% (usually). If an item’s price would be reduced to zero by modifiers, its price is -80% instead (minimum 1 coin).

As a natural extension of that, I've decided to make a list of qualities and materials using tags. They will vary in price based on the number of good and bad qualities they have. I know this one may not suit everyone, so don't read it if you don't want the extra detail in your campaign

Design

Damascus Wootz/Pattern Welding

+50% value

• Superior to Steel

Dwarven Armor

+150% value (only +50% inside a Dwarven settlement)

•  Armor removes the Clumsy tag for dwarves
•  -1 ongoing to Defy Danger with +DEX.
•  Superior to Steel

Dwarven Weapon

100% value (only +50% inside a Dwarven settlement)

•  Swap Reach for Forceful
• Superior to Steel

Elven Weapons (Elven armor is Mythril)

+250% value (only +200% inside an Elven settlement)

•  Mythril
• +1 Ammo

Notes: Used in place of the core Elven Arrows price is only 5 coins but stats remain the same.

Jagged

+100% value

• +Messy
• +1 damage

Orcish

+50% value

• Cheap
• Jagged

Stiletto

+50% value

• 1 piercing

Material

Crystal

+50% value

• Jagged
• Fragile

Dragon Anything

+250 value

• Armor Only: Provides the same Armor value against the element the dragon breathed (so a 3 armor suit protects with 3 armor for most things, 6 armor vs. its breath type)
• Weapons Only: The element that the dragon breathed is imbued within the weapon, giving it the +element tag (which logically affects weaknesses, resistances, and so forth). Whenever you roll 10+ to Hack and Slash and choose to deal extra damage, deal an extra d8 instead of the normal d6. You are still at risk.
• Superior to Mythril

Lightweave

+350%

• Superior to Elven
• Whenever you Hack and Slash or Volley, you can roll +INT instead of the respective attribute.
• If you are a Cleric who worships Sola, upgrade your damage to a d10

Mythril

+200% value

• Reduce wt. by 1
• Weapons replace Clumsy with Precise
• When you defy physical dangers with Mythril Armor, a 6- becomes a 7-9
•  Superior to Steel

Orichalcum

+400% value

• Ignores the "n Piercing" tag when dealing damage, but not the "Ignores Armor" tag
• Armors get +1 armor
• Weapons get +1 Piercing (though the tag is ignored against Orichalcum, it still gets a bonus point of damage for the purpose of normal penetration, thus breaking even with the armors)
• Superior to Mythril (probably worth a bonus forward, but that's up to the fiction)

Quality

Cheap (may represent “Pig Iron”)

-50% value

• For weapons, on 6- with Hack and Slash or Volley, reduce damage by -1 ongoing. Normally a -x ongoing calls for a circumstance that fixes it. This could be anything from bending metal back into shape, re-wrapping grips, refitting armor that's been knocked out of place, retying ties that have come loose, etc. For armors, a 6- on Defend or Defy Danger reduces armor by -1. Armor reduced to zero is destroyed

Fragile/Brittle

-50% value

• On 6-, the item is destroyed.

Superior

+50% value (minimum. Also add the value of lesser materials where applicable)

• Whenever the GM offers a worse outcome, hard bargain, or ugly choice, or says what happens on a 6-, the item cannot be lost to a lesser material.