Recently PBS's News Hour profiled author Ellen Ruppel Shell, whose book Cheap seeks to explain why discounts seem to be so appealing. Apparently there is a biological basis for this, as the brain metes out a small neurochemical reward when a material gain is anticipated. And it is specifically the anticipation of gain which triggers this response, not the item which is obtained. Conversely, the fear of regretting a missed opportunity presents a strong negative reinforcement with the same end result. This explains why there is never an end to the production and consumption of cheap useless crap.
Like this ugly thing: