The rule to thrift store pricing is that there is no rule. Many chains in their back rooms actually have a small # of departments managed by (in theory) a competent person who is able to sort, fix and price items in his/her field, usually books, clothes, electronics, appliances. Some have local volunteers -- self-appointed "experts", offenders on community service, or just regular folks -- come in from time to time to do this. But the general level of competence and knowledge, given the background of the folks who toil there, to be kind ain't always great, and is most always overwhelmed by the sheer volume of incoming junk.