We Need More Writers!
A host of cooking materials are falling like rocks because nobody needs food right now. Thanks in part to the scarlet buff that we all have in excess, and everyone working on other disciplines to get their back pieces, not many cooks are doing their thing right now. It's a matter of supply and demand, so when there's no demand and plenty of supply the price will drop.
I strongly encourage the purchasing of every cooking ingredient you see below its normal value. In particular...
Rutabagas, Onions, Carrots, Garlic, and Eggs.
Also... Grapes. People seem to think that the next Lion's Arch update will involve them. When word got out I told everyone on my email list and within a few hours the price had QUADRUPLED. There's no guarantee, but we're expecting "wine" to be part of a new recipe. Grapes make wine... so yeah there's a small chance they will be worth a ridiculous amount since there aren't many in the game right now. I have my doubts, but it's worth a little speculation.