In my current game, costs for districts like harbor are up from 60 base costs to almost 500 around turn 275 / 500. This makes it almost impossible to build districts in new cities since you cannot buy districts, only the buildings in districts. I know that there is a way to push these cities with internal trade routes, but it takes around 30 turns or so until trade routes can be reassigned and you would need many trade routes per city to see an effect. Currently I have 16 cities of which 4 are new founded (colonies for exotic resources) and another 3 are conquered and need to be adjusted. Number of trade routes is only 14 since harbors / commercial districts are so expensive that they take forever to build in the new cities. Actually I planned to found even more cities to prevent barbarian uprising in unsettled areas. My income is around 600 gold per turn (thanks to a Great Trader and internal trade routes), but prices are high. Purchasing a worker costs already 500 gold (15% reduction applied for Trade Republik) which is almost 600 gold unmodified. In turn 1 my city with pop 1 and no buildings except the palace had an income of 10 gpt while a worker costed 200 gold, so I could buy a worker every 20 turns for one city. With the current income, I can buy 14 workers for 14 cities every 12 turns, so despite the high effort of building harbors and commercial districts, markets, banks, stock exchanges in most cities with pop between 10-20, the income per city has only slightly increased due to 250% - 300% inflation for prices. On the other side research speed is so fast (5 turns per tech) that it is impossible to build all the new buildings and wonders in the core cities, e.g. a wonder still takes 20-40 turns for my core cities, a level 3 building between 8-14 turns. Modern military units take 4 turns in capital but around 10 turns in other core cities (single units, no corps etc.). Question : Is inflation based on number of turns, number of techs, policies, cities, districts, buildings or units built? Does the high inflation imply that you should stick to 4-8 well placed cities like in Civ 5 and should avoid expansion / conquest?