I'm trying to reverse engineer the Life Stealing part of the Sword of Life Stealing in the Dungeon Master's Guide (page 228).
Sword of Life Stealing: This black iron +2 longsword bestows a negative level when it deals a critical hit. The sword wielder gains 1d6 temporary hit points each time a negative level is bestowed on another. These temporary hit points last for 24 hours. One day after being struck, subjects must make a DC 16 Fortitude save for each negative level or lose a character level.
Strong necromancy; CL 17th; Craft Magic Arms and Armor, enervation; Price 25,715 gp; Cost 12,857 gp and 5 sp + 1,029 XP
The first question is, is black iron equal to cold iron? I can't find any other reference to black iron anywhere. But weapons aren't made out of iron unless it's cold iron, otherwise it's just steel. That the price ends in 15 rather than 30 implies it's not cold iron (which doubles the cost of the base weapon, and the longsword costs 15).
If we assume it's not cold iron than it works out to 315gp for the masterwork longsword, 8,000gp for the +2 enhancement bonus, and thus 17,400gp for the life stealing enchantment. Does that track?
If we do assume black iron equals cold iron, then it's 330gp for the masterwork longsword, 12,000gp for the +2 enhancement bonus, thus 13,385gp for the life stealing, from which we subtract the additional 2,000gp it would have cost to add it to cold iron, giving us a final price of 11,385gp. Does that track?
So which of these makes the most sense? Or have I made a mistake on my math or reasoning somewhere?