Buy crabs in the aquatic products market, not near Gucheng Lake. Crabs are good, much cheaper than those in Nanjing. It depends on the time. Sometimes the price of crabs will change, sometimes it will go up a lot, sometimes it will drop a lot, and the difference of two or three times is very likely, so it depends on your luck.
The same thing is the same. Of course, it will be cheaper on a fishing boat, but you should also worry about being not authentic.