[ry_ry]

Depends if the whole industry decides to take advantage of the opportunity to increase prices and blame the cost of oil or not.

It's the prisoners' dilemma, but applied to exploiting consumers!

[xyzzyz]

Yes, and in a prisoners' dilemma with thousands of players, someone is surely going to defect and sell their stuff cheaper to undercut the competition. I don't think I've ever heard about large scale collusion to fix prices in food industry, and I won't hold my breath for it this time.