Large (or Larger) Adamantine and Masterwork Weapon Costs

[steven_mallory]

Looking for a good ruling on the cost of Large and larger weapons when the PCs come upon them and try to use or sell them (say, looting Large and Huge giants).

The CRB states that weapons for Large creatures cost twice the listed amount. No problem there.

What about the cost of making a Large or larger weapon masterwork? Is the 300gp cost a flat amount, or does it need to be increased (doubled to 600gp?) for a Large weapon? I've seen GMs rule this both ways.

What about the value (and sale price) of a Huge giant's adamantine greataxe that the party wants to sell off (or that their Titan Mauler Barbarian wants to enlarge himself to use)? The entry for adamantine as a special material just says +3,000gp for a weapon, it doesn't give a poundage cost, or indicate that it necessarily changes by size category. Should it be a flat 3,000gp like a Small/Medium weapon? Doubled and then doubled again for increasing by 2 size categories above Medium (so 12,000gp)? Add 3,000gp per size category increase, so +9,000gp to the cost of a Huge adamantine weapon?

I can see arguments for any/all of these interpretations, but I don't see anything definitive in the rules to point one way or another.

[Taja the Barbarian]

This is actually a FAQ on this: You apply the size multiplier last, so special materials become much more expensive for larger items.

The only exception to this is the 'normal' masterwork cost, which is not multiplied.