In my opinion, I the bulk of them are rip-offs. I will not mention these auctions by name, but buyer beware. Sites showing a good price until you read the fine print and see you have to buy two packages because the price is only good for one person and you must buy two. I have found one legitimate site. You get a full description of cabin and cruise.
Cruises are always for two people.
Port charges are additional and that is clearly stated. I had an outside cabin as advertised. If you are going to buy at auction, be very careful. Hope this is helpful. Just came back from a four-night cruise and it was terrific.