[DM Question] Homebrew Item

[Rhaegar14]

Alright, I'm gonna have to go into a little bit of background first. In my campaign world, all fiends are basically the same faction. They also aren't even known to exist (like, period). The characters have been running into them, however, and their DR is causing quite a few of them problems. Now, the normal solution would be weapons made from a different mineral, but it really doesn't make sense for demons to be susceptible to one and devils to another.

I gave it some thought, and decided that after a few more encounters with the fiends, they would get these items called "Fiendslayer's Rings", which would make their attacks good-aligned for the purpose of overcoming damage reduction. But how should I price them (they would be given, but I still need to figure out how much they count for in total loot)?

[Riftwalker]

There is a ring in the Magic Item Compendium on page 122 (Ring of Brief Blessing) that, as a swift action, allows its wearer to treat its weapons a good-aligned for the purpose of overcoming damage reduction until the end of his/her current turn. It works once per day but can be recharged by burning a turn undead attempt for the day. It is priced at 1,000 gp.