Wow, it is insightful reading this post.
I don't haggle. I don't give yard sales either. I haven't been to one in awhile either, but occasionally go. Some of the ones I have passed by real quick somewhat recently didn't have anything of interest. Mostly I freecycle. I have gotten many needful and wonderful things that way and have given away some good stuff to others that way as well. I am amazed to hear that people actually steal from yard sales. That is sad.