I noticed that rushing a building's or ship's construction costs about 20 times the construction cost in coins. This seems awfully expensive. The Walkthrough 2018 by Frogboy specifically states that you're supposed to use your starting money to rush-buy stuff, but that ability is greatly limited by the biblical amounts of cash you need for just one building or ship!
Next I've noticed that when upgrading ships, the cost is only around 15 times the difference in cost. Therefore we now have the odd situation that it's cheaper to just rush-build an empty hull, and then upgrade it to the actual ship you want!
There is one exception though: if you try to upgrade a ship wihtout a colony module to one that has at least one, the upgrade cost explodes! It took me some while to figure out that this may in fact be intended, because after the upgrade, that newly branded colony ship suddenly carries 1B population. IMHO it would have made a lot more sense to just upgrade to an empty colony ship instead!
The questions these things raise are:
1. Why are things so awfully expensive to buy? Economy, research and production buildings are about on par with regards to the amount of resources they produce. I could understand, say, a triple or quadruple cost for rush-building. But 20 times? Really?
2. Why is upgrading cheaper? Not that it's anywhere near cheap - we're still talking about at least13-14 times the cost difference, and often more.
3. Why does an upgrade to a colony ship need to add population? And add half a fortune in cost?? That doesn't seem to make sense.