Magic Armor / Weapon Cost Question

[Flashblade]

Hello friends,

I am having a disagreement with people based on how we have each always treated the cost of magic arms and armor.

Version 1: Base Item + Enhancement Bonus
Version 2: Base Item + Masterwork + Enhancement Bonus

Version 1 has a +1 longsword cost 2,015 gp.
Version 2 has a +1 longsword cost 2,315 gp.

Off the top of my head, I do not know of where to clarify this. The reasoning for Version 1 is that all magic items are assumed to be masterwork-quality already so the masterwork cost is included. The reasoning for Version 2 is that an item must first be masterwork before it can become magical, therefore that cost should be included.

Which way is the rules?

[kinevon]

The rules are that you can only enhance a masterwork weapon. Some materials are masterwork by default, so would not have an additional cost, like adamantine or mithril.

So:
Longsword: 15 gp
Masterwork: 300 gp
Masterwork is done at the same time as longsword, so: 315 gp
Enhance masterwork longsword to +1: +2,000 gp
Total: 2,315 gp

Note: The next step is a place where people sometimes get confused:
Make a +1 longsword into a +2 longsword: +6,000 gp
Make a +1 longsword into a +1 flaming longsword: +6,000 gp

Make a +2 longsword into a +2 flaming longsword: +10,000 gp

For examples of actual weapons following these rules, check out some of the named weapons in the Magic Items chapter.

Example: Assassin's Dagger: 10,302 gp
Dagger: 2 gp
Masterwork: 300 gp
+2 enhancement: +8,000 gp
Special property: +2,000 gp

Also, that section points out that alchemical silvering does not make a weapon masterwork, see the silver dagger, masterwork entry.

[Flashblade]

I see! To continue your examples:

breastplate—200 gp
masterwork breastplate—350 gp
+1 breastplate—1,350 gp
mithral breastplate—1,200 gp
+1 mithral breastplate—2,200 gp

Is the above correct?

[Deighton Thrane]

You're right on the masterwork and +1 breastplate. But it costs 4000 Gp to craft a medium armor with Mithral, so it's;
mithral breastplate-4200 gp
+1 mithral breastplate-5200 gp

[Flashblade]

Deighton Thrane wrote:

You're right on the masterwork and +1 breastplate. But it costs 4000 Gp to craft a medium armor with Mithral, so it's;

mithral breastplate-4200 gp
+1 mithral breastplate-5200 gp

Ah, right. Gotcha. Thanks again!