What are the differences in prices for Chongqing Three Gorges cruise ships

I have been searching for which cruise ship is good for the Three Gorges Tour. I have checked the cruise ships, but I haven't found anything special. There are both good and bad ones. I really don't know which series to book? What is the price difference of Chongqing Three Gorges Cruise? The official website for booking tickets for the Meiya Three Gorges cruise seems to only be able to check ticket prices and which ships...!!!