I have a Heavy Masterwork Mace.
How much would it cost to get it to +2 and give it Valiant ability?
Would I have to pay just for +1 Enchant bonus since the Mace is already +1 from being Masterwork? Or do I have to pay for +2 Enchant bonus, but still calculate additional +1 Masterwork damage bonus when I deal damage, so in essence the mace deals +3 extra damage (+1 from Masterwork and +2 from Enchant) on top of its other standard bonuses such as base attack and strength?
Thanks in advance!
Regarding the masterwork property:
1) The mace is not already +1. It provides a bonus to attack of the same type that magic does, but it is not "a +1 weapon."
2) The masterwork property never dealt extra damage, it only gave a bonus on attacks.
3) Because the bonus on attacks provided by the masterwork quality is also of type "enhancement", it basically becomes worthless once the weapon is made magical.
Now, for the magic portion:
The Valiant ability is treated as a +1 bonus for pricing the weapon. That means a "+2 valiant" weapon is priced as a +3 weapon, which would be 18000gp (plus the nonmagical prices you already spent.) Note that, although it costs the same as a +3 weapon, it isn't actually a +3 weapon - it won't automatically break cold iron and silver DR, for instance.
Once you have the weapon, the mace will provide a +2 enhancement bonus on attack and damage rolls (plus Strength, bonuses from feats, etc) and break DR\magic.
Thank you so much!
I should bookmark this reply because it answers so many questions and clarifies so many things I wasn't sure about!
Okay, since the Valiant ability already treats the weapon as having a +1 bonus, I should just go for additional +1, I don't have enough gp to go for +2 quite yet. That would be 8000 gp in that case, if I'm not mistaken.
Start with the price of a masterwork mace. Add the price of a +3 effective enhancement bonus (+2 enhancement, plus +1 for valiant). The result is the total price of the item. The resulting item has a +2 bonus to attack and damage rolls, bypasses DR/magic, and has the additional conditional damage and bonus to some combat maneuvers granted by valiant.
Example: A +2 valiant heavy mace has a price of 18,312 gp.
Edit: Since you're starting with a masterwork heavy mace, the price to have it enchanted is 18,000 gp. The resulting item is as above.
Edit the second: Yup, 8,000 gp.