Wand Adept [3.5 PRC, PEACH]

[Debihuman]

Technically you are correct though it doesn't specifically state that rods can't duplicate spells. However, to be fair, rods probably shouldn't only duplicate spells. For example, a rod of alertness lets you duplicate spells (as well as do other things), so it's possible.

Skip Williams (of Sage Advice) wrote that the defining feature of a rod is that "it has multiple powers that don't duplicate any known spell" except the rod of alertness proved him incorrect. See Making Magic Items (Part 5) in the WotC's archives if you are so inclined. Sorry I don't have the link.

That said, there's nothing inherent in the rules that specifically prevents you from crafting a rod of casting one spell only though it's boring and expensive.

The cheapest way to make a single spell item is to make it a staff even though the OP is fixated on making it a wand.

Like a wand, a staff has 50 charges, but you can double the charges used to half the price. The 375 price is the same price for wands and staffs. 375 gp x 9th level spell x 17th level caster level x 1/2 = 28,687 gp. Cost to create is 14,343 gp, 573 XP and takes 14 days.

If you can earn more than 28,687 gp by adventuring for 14 days, then is it really worth making the staff? The time consumption and XP cost really makes crafting magic items such a pain even more than the gp cost. You can always get more gp. You can't get back the time and I've never liked the XP cost of magic items, so I house rule it away.

Debby