I have done this before, but only because my original offer was a low ball one and my travel party increased in size and some extra room would be worth it. My auction bid was accepted, but still about $5k cheaper than they off the rack price for a 2 bedroom Haven suite. However if you already put in a good bid and increasing it either makes you a little uneasy OR the bid now doesn’t make the cabin a good deal anymore….hard pass. Yes, this is absolutely a way for NCL to maximize revenues but you still can get a great deal if you are vigilant