http://en.wiki.tycoon-world.com/index.php?title=Manual
"Additionally to the possible fixed costs, all three warehouses still cause costs for every stored unit:
" Raw goods warehouse: 2% of production costs per unit"
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Gems (harbor) cost: $7.500
I bought 1 unit of gem in the harbor and my total storage cost raises $300
storage cost= 2% = $300
100% = $15.000 !?!
So the cost is 4% for gems?
storage cost= 4% = $300
100% = $7.500 !?!
Maybe it is happening with gold and silver too... I didnt saw yet.