I'm reviewing as a buyer and not a seller. I've not sold to Half Price Books.
First off, I like there are are visible staff on the floor that are available for help. I feel like many places, in general, under-staff the floor.
The staff here are VERY HELPFUL. I inquired to a staff-member about a topic I am interested in, and they engaged another co-worker, who then engaged another, who all helped me find resources and gave me encouragement on my project.
The facility is large and they have a decent selection. The clearance section was a bit intimidating because I couldn't see a particular ordering for those books. Perhaps I didn't look into that enough to figure it out.