Board Thread:Questions and Answers/@comment-26494666-20160212181401/@comment-24722167-20160213203609

You do have to be allied with Dark Elves. However, after looking into the Yrm location through the game files to spot any other requirement, it looks like it's not actually possible to visit the shop due to a bug. Basically, although the Yrm shop has been created, there's no link to it from any location. What a bummer.

I'm  at least  going to fix this for The Protectors (0.8.6), but for now, the second best shop to buy items from is Drak Dum. They charge the same amount as Siria (110%) but Drak Dum can get ahold of better items. You also need to be allied with Dwarves.