Reply from Agony Uncle
From what you described the transaction took place more than a month ago. In law he is estopped or precluded legally from complaining that the price is too high or that there is problem on the i-Pod. In law there is a maxim “caveat emptor” ie buyers beware. So you need not refund him and if he decided to sue you the legal fees involved could buy him several brand new i-Pad.
Under this doctrine the buyer could not recover from the seller for defects on the property that rendered the property unfit for ordinary purpose. The only exception was if the seller actively concealed latent defect in otherwise made material representation amounting to fraud.