So everything ive read and seen says these fish oils should have been taken out of vendors stores once the live game launched, and were taken out of some stores. This item is used in cooking recipes and also obtained from every fish in the game if you extract it from them. This extract feature is made USELESS by having this item in vendors, which further makes me believe it should have been taken out.
The vendor that still has it is Hanul swiftgale hes a trade supplies vendor north of the tailor trader for horde players.
for only a few silver each ive bought my fair share of them in hopes it will be removed from the vendors later! good luck friends