Are you comparing like with like? Were the books 'bestsellers'?
I find that for instance Read's are extremely competitive on the very limited number of bestsellers they stock, but that their selection is very small, whereas HF or Waterstone's have a vast selection but may not always be as deeply discounted on certain bestsellers.
Are Eason's buying Read's?! I absolutely hate Eason's! One more extension of their vice-like grip on the import and distribution of books and magazines in Ireland...