For anyone who doesn't know how this works in this image I have put one item of each into the box to show the price that the balloon is giving you for it.
Gold 48 coins
Carrots 12 coins
Blackberry Jelly 93 coins
Lemons 20 coins
You have to load at least 2 of each item, so doing that in this case would bring your total up to 519 coins. Now to make up the difference to the required amount of 2900 coins you can load any of the items in any quantities provided you have two of each as a minimum.
If you were to load just carrots because they are the cheapest/easiest to get you would need to load 198 of them. You would have to find them in the market within 4 hours before the balloon goes and the carrots alone would cost you 5544 coins to buy. This would give you 1 trade ticket. You need 45 trade tickets for the gold prize.
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