Forget the Crit multiplier. Extra damage from critical hits is voided by 36kgp, so while Kaorti Resin is an interesting possibility, it's really not practical in any sense of the word.
The Pitspawned weapon template adds +2 to the confirmation roll for 1kgp, and is a useful addition. Something overlooked is that it also adds a 10% discount to the magical part of making a Sword of Life Stealing out of one, which applies a negative level on a successful crit and gives temp HP. Note that this discount actually pays for the cost of the weapon template and then some. Note that the base item is a +2 weapon, so you could, in theory, swap that out for a +1 Enfeebling (since it'd be the same cost).
~300gp for the weapon + 1000gp for the pitspawned template + 24,400 * 0.95 for the magic = 23480 gp for a +1 Enfeebling "Sword" of Lifestealing with an extra +2 to critical confirmation (you're probably gonna use a Kukri as the base item, anyway).
vs.
~300gp for the weapon + 32000gp for a +1 Enfeebling Enervating weapon = 32300 gp.
9k savings, plus I get better stuff? I'll take that...
EDIT: Nevermind, it's 10% to the raw material cost... fixing math.