Fun game poor economics.
Developers are greedy. Rubies are overpriced and trade at less than 1:1 for stone (an infinite resource). Obviously the developers deserve to make money but not finding an objectively fair price and trade value for their games purchasable currency is lazy or malicious, I am not sure which to hope for. Fun game with a pay wall that is relatively greater than a large budget console game.
Kaididdy about
ANNO: Build an Empire, v1.3.1