I agree with Anobix, cook.
Anyone can use cooked deviate fish (savory deviate delight) so more buyers = more demand = more money.
Only people with the skill and recipe can use the raw fish. So less demand, plus it's not a recipe that people will use to skill up (too expensive to buy the raw fish). therefore less demand = less money.
I would try selling some in the neutral AHs (BB. Gadgetzan), as they might go for a little more money as higher level toons will check there, but this isn't always the case.