I could recommend you start by checking the Mystic Pearl for +1 returning silver shurikens. They can be "upgraded" to holy later (since you can sell them back at full price) when you have the cash.Are there special rules for magical weapon costs if for ammunition? I was thinking of having Lem the Cook purchase some shurikens as throwing weapons for his upcoming adventure, but they only do 1-2 hps of damage.
No big deal. We are going against undead, so I thought I would get silver shurikens, with a holy special ability tacked on. This would effectively make the shurikens +3 weapons for the sake of cost (+1 base magic bonus, +2 for the holy ability). Checking on the Pathfinder site, that would mean a whopping 18000 coins for 50 +1 holy shurikens. Lem has over 7500 gp right now.
So is it possible for me to purchase at fractions of the cost. Say I purchase 20 +1 holy shurikens for 2/5 the cost, or 7200gp? Tacking on the silver alchemical property increases the cost by only 2gp each, but make it so the shuriken will only do 1 point of damage, maximum. Still, with the holy property attached they will do an extra 2d6 to undead.
I would lose one of these shurikens each time I threw it, right? So I would lose about 362gp per throw. Wow....

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.