Treasure Hunt is a feature in KoP. You can do daily up to 2 free drawing, but you'll always get the "worst" item possible. After 2 draws, the costs are 30 Belly, +15 Belly with every new draw (30, 45, 60...)
There are 14 items, and if you want to get every item, you should spend 3 more draws on 2 days, and 2 more on 1 day.
That makes: 2x (30 + 45 + 60) + (30 + 45) = 345 Belly
Otherwise: (30 + 45 + 60 + 75 + 90 + 105 + 120 + 135) = 670 Belly
You can get there Bellies, Amor, Gems, Drilling Stones, Equipment, Gold and Vitality, but there are 2 specific items, that are worth putting your Bellies in.
I suggest you to spend your bellies if you want to get these two items. You'll always get them last.