Higher resource output past 15

U can always capture a fully upgraded city lol

Paying for resources is not the issue. I don't mind paying 10+ coins for an upgrade, but the output should reflect the price. I was expect the level 16 upgrade to be 2-3x the output of level 15..simply because you are paying for the upgrades now. I think having a fairly large increase in output would be a good incentive to do so. I personally will stop at level 16 as I don't see the level 17 output quite worth the 25 coins.

Well put shin. If they wanted to make some money they'd actually make it worth it. I will not be updating anything else past 15

Well i think they already make enough ways for paying customers to have an advantage. . .a huge increase in output would only end up making the game more 'unfair' in most peoples eyes, but thats just my opinion

The devs would most likely end up with more money in their pockets if they increased the output of the coin requiring upgrades. I kept all my resources at level 15, it just doesn't seem worth it to blow coins for a relatively small benefit.