cheaper price

Again my beloved customer came in and said 'the other shop offers better price'..'I can get more crystals with cheaper price'..so if you were me, what would you feel or say?.Sometimes, it is sarcastic to say'..so,you can go and buy there!'.But according to bussiness mentor, we should not say such unprofessional answer..I think most shop owners will face the same situation..BE PATIENT.