I'm sorry I don't have an answer, but I would like to know the same thing as you. I saw that same line and it made me think twice about possibly publishing here. My really confusing point is the part about charging my credit card for more returns than sales in a pay cycle. They pay 60 days in the hole, so I don't know why they would have to charge my card. I'm still trying to find an answer for that too. I guess I'll have to keep up with the two discussion topics to see if you get an answer to your question, and if I ever get a question to mine in the other post.
You set the price of your ebook at B&N. If you sell it for less somewhere else then B&N has the right to change the price.
I had this same question about Amazon and I learned that it is the same there.
PubIt! follows a standard retailer model: you, as the publisher, set the list price for your books, and we, as the retailer, set the customer price for your books. Regardless of the customer price that we set, you will be paid based on the list price that you set. We will not change your list price.
The PubIt! Team