JUST FYI You can fish all day and save the fish in groups of ten. The fish monger wants fish for rewards. You can sell the different fish on your vendors and make some gold. Why? A lot of people would rather buy the fish for the fish monger quest vs. fishing for an hour. Prices. Well thats up to you. But I bet you can get 5k to 25k a fish depending on the difficulty. NOW thats for common fish. There are lots of rare fish. What the sell for I dont know.