My view when this ever happens to me, is that I was willing to pay the price (for the item) � the fact that someone might be selling the same item for less (unbeknown to me), or the seller subsequently drops the price does not faze me.
My partner regularly shops at a well known high street fashion store, who will refund an item (purchased within the last 7days � tags still on), no questions asked. On a number of occasions she has returned an item (paid for at full price), and purchased the identical item in the shop�s sale.