Food in Disneyland is expensive and it depends on what you are going to eat. Prepare 500HKD for food is enough. Terminal fee in HK AIrport is 120HKD. Along with other taxs, it should be nearly 400HKD. Souvenirs in HK disneyland, about 100HKD. The exchange rate in the airport is not very good. If you want to change a lot, better at the downtown area. If you just want to exchange a little, the rate difference id not big in fact.