Yes, that Pretty Pussycat, the adult store on 3rd Street next to the old Highway 97 gas station. I stopped in there today, idea-and-costume-hunting, and wow, they have a really big selection of stuff—some adult/mature themed naturally, but a lot of mainstream things. Their main floor in the front is women’s costumes, and upstairs is men’s. (The really adult stuff is in the back, probably somewhat displaced for the Halloween setup.)
There’s a lot of licensed costumes especially—characters from movies and such. "V for Vendetta" (which no one else in town has; I was previously looking online for it), Star Wars costumes, the Burger King, like that. "Regular" costumes too, and a good selection of masks and accessories.
Full costumes range in price from around $40 and up (though there may be cheaper ones, I didn’t look at everything), which is comparable to the Halloween Headquarters prices. Various other accessories seemed reasonably priced. If you’re on the hunt for a good costume, definitely check it out.