The following uses the famous Wolf Spear of Ulfheonar from Doom of the Savage Kings as an example of the costs that would need to be associcated to construct such a device using the sword magic spell (page 229 from the Core Rulebook).
Tl;dr: It cost somewhere between 75,000 and 105,000 gp to create.
Ulfheonar’s wolf-spear, better known simply by its master’s name, is a magical wolf spear.
- +1 to hit
- +1 to damage
- +1 to initiative rolls
- Intelligence: unknown
- Desires: unknown
- Alignment: unknown
- Bane(s): Wolves and magical creatures that escape via gaseous form and plane shifting
- Bane effect: pinning creatures and preventing them from escape (see type 3 magical powers below)
- Special purpose: presumably to kill wolves and other magical beasts
- Type1 natural powers: none
- Type 2 combat powers: instigator, +1 to initiative rolls
- Type 3 magical powers: Pinning Creatures: On successful hit, creature is pinned (reducing target AC by attacker’s Strength bonus). By sacrificing his actions in a given round, the wielder can maintain the pin on the target with a successful contested Strength check. With the spear, heroes can even pin magical creatures, preventing them from assuming gaseous form, teleporting, stepping to another plane, and so on.
Cost to Construct
The estimated gp cost to create using the cost estimates listed in the sword magic spell (page 229).
- 5000 gp (up to 15000 for +1 to hit, damage, and initiative), materials
- 20000 (up to 100000… Probably somewhere around 40000), bane—note, this might be double counted with type III cost)
- 20000, type II cost
- 50000, type III cost
- Min: 75,000 – max 105,000