As a side note, has anyone tried to do the math and figure out what it would cost to take a new city all the way through the game by just spending diamonds?
Hard to estimate, but I'd assume at least a few thousand. It depends on what you mean by "take a new city all the way through."
Do you mean:
-buy all the premium expansions? All 29 expansions are 155,550 diamonds.
-buy all magical residence and workshops? Hard to tell, because variable numbers, and you might be able to upgrade some for free with blueprints. But some folks like JPS and others mentioned spending a few hundred per chapter just to manage residences and workshops.
-buy all magic culture? Again, a moving target, based on participation in events, and needs, and desire to keep your culture at certain levels, and desire to have "the latest and greatest." But probably a safe bet to assume 50K or more diamonds during the levelling up progress.
-impatiently rushing buildings? Completely un-knowable.
-buying FA badges? See above.
-buying "extra chances" during Major Events? Presumably someone is spending $20 bucks or so every event for a few more rolls at preferred daily prizes, or to guarantee the Third Grand Prize.
Assuming you bought the max amount diamonds (11,000 diamonds at $80), and best case scenario you bought them all on 100% diamond bonus days (22,000 diamonds at $80), you're spending 275 diamonds/dollar. That means $565 on just expansions, plus another $200 on premium culture, plus ?$1,500? $2,000? on buying and upgrading residences/workshops through 12 chapters?
Damn, that's a lot for a single game.