For anyone who hasn't done the math:
At 12/hr x 3 (so bronze swords or something) assuming you started at the beginning of the event - you will make 864 balloons a day (call it 850 for travel time).
850 * 14 days = 11,900 balloons
But you need 15,000! No worries - you will get 600 from quests, and 100 per day from the daily, for 2000 more, 13,900 balloons.
But that's not 15,000! Still, you get 310 from the achievements (have 10 cakes placed on you) - but let's ignore those. You're short 1,100 balloons and very sad right now.
However - you get one petite cake from the quest, and one enormous from a door - even if self-placed, that's 16 hours of 50% and 16 of 100% = 288 and 576 = 864 (say 850 for travel time). Still 250 to go.
But that's only ONE MORE SELF PLACED Petite Cake! That's 80 dough and 100 candles, or 360 candles.
Getting 720 candles from explorers and adventures should not be hard for anyone. There is no need to buy dough in the trade office, unless you want to go beyond the 15k for the 1k repeat rewards.
And the double ballista may be worth it, but that's up to you.
You only need a total of three buffs to get to 15k.
You need 720 candles to make the two-self made buffs (assuming you can't get any dough at all).
I didn't; I ignored the achievements entirely - with them it's even easier; perhaps no dough/candles at all.
The only thing you need to buy is the 50 of cake or candles for the one quest. If people really want to buy cake beyond that, more power to them, but don't be surprised that the market is not very favorable for something in somewhat short supply that you probably don't really need, even more so if you are criticizing people for "gouging" because they could just not sell at all.
This is a pretty relaxing event compared to something like Easter or Halloween. 15k balloons should be pretty easy to come by for most people. As long as you have the resources handy, you can just set it and forget it for 2 weeks and self drop the occasional free buff if you want. In terms of community contribution and additional rewards beyond the top limit, that may take a bit more effort, but just for the main prizes, I don't see why anyone would struggle very much.