用Priceline预订宾馆并支付后，到店时还需要刷信

第一次用Priceline，请多指教。
我先后在Priceline ListView、和Express Deal里预订了巴尔的摩和华盛顿的宾馆，Priceline也已经从我信用卡里划走了包括税金在内的宾馆全款。那么去住店时还要再支付什么钱么？
如果是押金，什么时候能退还到卡？
我看到Priceline在我的订单里有如下的提示，注意都有mandatory（强制性）收费：
==== 对于通过List View预订的酒店====
The credit card is required for any additional hotel specific service fees or incidental charges or fees that may be charged by the hotel to the customer at checkout. These charges may be mandatory (e.g., resort fees) or optional (parking, phone calls or minibar charges) and are not included in the room rate.

==== 对于通过Express Deals预订的酒店====
Mandatory Fee: This hotel charges an additional $1.50 per room per night. This fee will be charged to you directly by the hotel. Mandatory fees are not optional and typically cover items such as resort fees, energy charges or safe fees. The amount of the charge is subject to change.