I rarely see these for sale at the AH- I thought that I had seen the Vegie seeds for sale in a shop or by one of the outdoor vendors. If anyone in Asura is selling Fruit (or Veggie) message my Mithra Cindycin.
Go to Bastok, take one step outside, whack a sapling and you'll more than likely get some seeds. Usually they're vegetable seeds, but sometimes they'll be herb or grain seeds.