How is the price for a sleep arrow determined?

[domino]

A bit of backstory. I've made a character who is a primary bow user turned paladin of love. As such, I figure an arrow of love makes sense (as he becomes more and more like Cupid.)

Looking at the various methods, I decided to adapt the Sleep Arrow by switching the Sleep for Charm Person spell. The sleep arrow costs 132 gp. Now, I can see where they got the majoriy from (CL 5 * Spell Level 1 * 25 for single use item) and another 3 silver for the masterwork quality for a single arrow.

But where does the other 6.7 gold come from? The changing regular damage to magical nonlethal? And if so, what is it considered to be, in terms of pricing? A secondary effect?

 

[Darkness]

mw arrows cost 7 gp each.

 

[Diirk]

You can’t add the masterwork quality to a weapon after it is created; it must be crafted as a masterwork weapon (see the Craft skill). The masterwork quality adds 300 gp to the cost of a normal weapon (or 6 gp to the cost of a single unit of ammunition). Adding the masterwork quality to a double weapon costs twice the normal increase (+600 gp).

20 arrows is 1 gp, so an arrow is 5 silver each. 5 silver +6 gp for MW = 6.05 gp. Maybe they just rounded up ?

 

[Darkness]

50 MW arrows would be 302.5 gp (1 gp per 20 arrows, +300 gp for MW on 50 arrows), so each MW arrows would be 6 gold 5 silver. Maybe they just rounded it up.

Yeah, the example on p.122 of the PHB makes it seem like they do. It says that 10 mw arrows cost 70 gp.

IIRC the mw arrow price dates back to 3.0 but was easier to find in 3.0, where there was a table for such items.

 

[domino]

Ah. Now I get it. For some reason, I was thinking that 20 arrows made a single unit of ammo, as that's how it's normally bought. Thanks for clearing that up.