To answer Vivik, these are not only available through the NPCs, they can also be had by Treasure Casket:
Cape Teriggan (normal)
Ro'Maeve
Valley of Sorrows
Otherwise, yes, you would be right that it wouldn't make sense for these to sell for less...but I am glad they sell for less, so that cooks can get these for cheaper.
u can also get these from campaign loot so thats why people r dumping them on ah at very low prices. i try and buy them up at this price but usually someone else alrdy has.
If these were more common, I would love it if they sold for less than the NPC, but on my server there's no more than one jar a day in the AH. Cooks need stacks of this stuff to make sushi, and even if only to make up for the occasional break, these need to be more common. The only real thing selling it for 1k each does is screw up the profit calculations.
I'm not asking people to raise the price, though, I'm just saying SE needs to make this a more common drop. People want cheap sushi, we need cheap wasabi to do that, therefore there needs to be more cheap wasabi to go around.