I have a player who has Craft (armorsmithing) and wants to craft himself some armor during some in game downtime. He recently acquired a pair of mithral breastplates as loot and wants to reforge then into a set of banded mail. Now, since he has the raw material, just needs to melt it and reforge it, what should the cost be? It doesn't make sense for the full +9000gp for mithral heavy armor, but I don't want to just give it to him for time at the forge either. What would be a fair compromise?
Well, mithral Banded Mail weighs 17.5 lbs. Two mithral Breastplates weigh 30 lbs. If we're going by the pound, that leaves 12.5 pounds of mithral leftover.
At the same time, the difference in mithral price between heavy armor and two medium armors is 9250-8400=840gp.
I don't think it's unreasonable for him to craft heavy armor by melting down two medium armors so long as he has enough mithral from the medium armors to do it. If he invested the skill points to be a good enough crafter to do this, it feels like a reasonable application of this skill, especially since crafting through practical blacksmithing reduces the cost by a third.
Compared to the cost of mithral banded mail, 840 gp doesn't seem like a lot. If you want to make a decent compromise, you can say that the additional 12.5 pounds of mithral were consumed in the crafting process because of the impurities associated with melting down and reforging armors.
If you go by cost, remember that material costs for mundane items is 1/3rd the items price. Mithral heavy armor adds +9000gp, but only 1/3rd of that represents mithral cost (3000gp.)
Medium mithral armor adds 4000gp to the cost, of which 1,334gp worth would be mithral. With two sets of medium armor, thats 2,668gp worth of mithral.
With as little as 332gp worth of additional materials, he could craft a suit of mithral heavy armor.
(The real problem will be the time. Crafting anything from mithral takes forever. Assuming he only just meets the required DC of 17 if he takes 10 on the checks, then it takes about 320 weeks to make mithral banded armor. Note that a normal suit of banded mail can be made in under a week. You can add +10 to the DC to craft faster, so if he can manage to take 10 and meet a DC 27 the armor can be done in about 127 weeks. I hope he has a lot of down time, or a massively high Craft modifier.)
Also, he would be better off just selling the mithral breastplates, and buying more mithral (assuming its available). A mithral breastplate is worth 4200gp, so sells for 2100gp. He can sell both breastplates for 4,200gp total, then buy the 3000gp worth of mithral he needs for his heavy armor, and still have 1,200gp left over.
Mithril crafting by the rules is ridiculous.
http://paizo.com/threads/rzs2p71k?How-fast-can-you-craft-a-Mithral-Full-Pla te
This thread has some discusion on it and suggests various house rules (and 3rd party material) if you desire.
Personally, I just ignore the added cost of the special materials when determining crafting time. So armor and weapons made out of special materials take no longer to make then their steel (or wooden) counterparts.
In my games, we use "Making Craft Work" for the crafting time and DCs.
For that situation, I would say that the mithral breastplates are worth 50% of their cost for purposes of reforging (just like if he sold them and bought new supplies), and he can use them to directly craft the armor he wants, with some leftover scrap.
So:
Mithral breastplate = 4200g cost = 2100g value
x2 = 4200g worth
Mithral banded mail: 9250g cost = 3083.34g crafting cost
Result:
Mithral banded mail and 1116.66g mithral scrap (trade goods)
Thanks for all the help. In the end, he changed his mind, since using the Mithral breastplate actually increased his AC by 1 with the increased Dex mod, so he's just going to spend a week resizing it to his frame. (He's a half-ogre, they got it off a drow. There's going to be a LOT of tweaking of that armor, so a week works for me.)
I will be using some of these alternate rules in the future though. The crafting rules as they stand are a bit useless and do need tweaking. If anyone has any more ideas, please, keep them coming!