Use per day items are useful and their price can go up to ridiculous numbers simply because they are a way to reduce clutter in the inventory and not bother investing in UMD necessary to use the scroll version of it. However, they all have limit to their usefulness: each use per day property has a fixed caster level which, in some cases makes it not a very worthwhile investment. (off the top of my head:
In that particular case, I would say someone overpaid because blackforest's Protection of Alignment has CL of 3 which doesn't last long and you can get a scroll with same properties for less than 50 GP as far as I remember.
On the other hand, that very same staff has negative energy visual effect which might have been the sole reason someone bought it
