Over all nice concept. There is not just flaws in the calculations of upgrading production.... additional flaws are found in the costs of the upgrades as well as the transporting goods to be sold. For example horse carts are the best for transporting however they are outdone to quickly after 3 tier 2 product upgrades. As said before flaws in gains exist as well. Gave 3*'s for effort instead of 2*'s. Feed back from devs on reviews is great hence the 3rd star