기준금액 : base amount 환율우대사유 : reason of favorable exchange rate

Here are the individual meaning of the words. - 환전 = currency exchange. - 기준 = basis or reference. - 금액 = amount of money. - 환율 = exchange rate. - 우대 = special favored treatment. - 사유 = reason, basis. So, - 기준 금액 = amount to be exchanged. - 환율 우대 사유 = basis for applying special favored exchange rate (such as privileged client status, exchange coupon, etc).