The BASE Sell Price is based upon a 3 star rating for the fish.

For instance, the Oyster in my picture is a 1 star Oyster. There is a strikethrough on the 25 gold showing that an average Oyster would fetch 25 gold, but this is a tiny catch. Here are the estimated prices I'm seeing from the variety of fish I've caught thus far:

1 star = rounddown BASE X 0.2 (See Oyster 1 star image)
2 star = rounddown BASE X 0.5 (See Thilivern Turbot 2 star image)
3 star = BASE (See Netherwind Needlefish 3 star image)
4 star = rounddown BASE X 1.5 (See Gar of Gradockh 4 star image)
5 star = BASE X 3 (See Netherwind Needlefish 5 star image)

So, basic math example to follow.

If you had a fish with 100g BASE price using the formulas above it would work out like this:

1 star = 20g
2 star = 50g
3 star = 100g
4 star = 150g
5 star = 300g



I recommend you sell any fish at 4 star or higher PRIOR to completing quests that consume the fish, so you don't accidentally lose out on those gold to buy fancy hats!

Happy Fishing everyone!