So I chatted with Priceline. Here is the response: Charles: Whenever you place a request for a hotel, we attempt to disclose the average Hotel Fee for the area and star level you select. Once a hotel accepts your offer price, we will know the actual Hotel Fee and it will be displayed on your Accept Page. Please be advised that we did not charge you for these fees since the hotel will charge you directly at check out. In some instances, the Hotel Fee will be the same as what it is displayed on the Contract Page; however, it could be less or it could be more.
Jo Deppe: I have never encountered this before. How do I know when to expect it, so I do not accept it accidently?
Charles: Please make sure to review the summary of charges everytime you submit a request.
Jo Deppe: Is this something new?
Charles: Yes, it is. We are now trying to disclose the fee before booking so that this will not caught you by surprise when you get to the hotel.