I don't support anyone selling chocolates to others whatsoever. Therefore I'm going to undermine everyone's buisiness right here and now.
Make two alts. Buy chocolate ingredient. Sell to self for 2c. Each of these alts will now have 0.70c. Event lasts 30 days. 30*.7 = 21. Sell a random drop back to the alt for 14c (21*.7 = 14.7), do it again with other alt to get 28c. You spent 60c total, so subtract 28c = 32c. Congrats, you just made 30 chocolates over the course of the event for a grand cost of 32c (Although you need 60 to start). Now stop buying chocolates from the people trying to sell ingredients for more than 1 c and the full chocolate for more than 3c.
If someone working at CS sees this, make these items untradable between players please. It's pretty stupid how many people are trying to make a quick grab for OC just like with the winter event.