There are a lot of candy value questions. I just thought I'd jump in and say something...
There is no way to judge the value of the candy currently. We won't be able to know till the end or near end of the event. And that's for a number of reasons. First, we don't know how many pieces of candy we're allowed to collect yet. Second, the candy is used to trade for pets (and items), so until the event is over, we won't know the rarity of those pets, which all depends on how many people manage to get (and how many outcomes for the growing ones).
I'm sure there are plenty of people who will disagree with me, but that's just my two cents.