I was just minding my own business, trying to calculate the resource values for various armors and weapons from the units in the game... and as far as I can tell... there is no rhyme or reason=) Some things seem obvious, like:
Spear: res=2
Axe: res=3
Short Sword: res=3
Flail: res=5
Helmet: res=1
Javelin: res=1
Round Shield: res=2
Leather Cuirass: res=1
Leather Hauberk: res=2
Ring Mail Hauberk: res=4
Ring Mail Hauberk: res=6
Dagger / Poison Dagger: res=0
Minimum Resource Cost per Unit: 1
..but if you build on from there, you run into problems=) So, unfortunately, there is no constant value for the resource cost of any given weapon or armor in Dominions II.
Even within a nation there are inconsistancies... try Abysia, for example, and calculate the cost of a Plate Hauberk...
-Cherry