Farm upgrades with coins?

How far can farms be upgraded beyond level 15 with coins?
Is it 10 coins per level or does the price go up the higher the level?

If you had max farming tech and fully coin upgraded croplands what kinda food output would you be looking at?

Thanks!

10 Level 16
25 Level 17
40 Level 18
60 Level 19
90 Level 10

RESOURCES GAINED PER LEVEL (Resource Buildings)
1. 6
2. 15
3. 26
4. 42
5. 59
6. 85
7. 168
8. 230
9. 319
10. 420
11. 560
12. 712
13. 891
14. 1,079
15. 1,280
16. 1,500
17. 1,820
18. 2,080
19. 2,400
20. 2,695

4 Crop Resources at level 20 with 10 tech is 21,560 output.

Thank you for that great response.

Wow thats alot of real money to upgrade them!

900 coins for all 4 not using speedups :P

Not quite worth it considering the output is minimal. If you have the coins to burn, then go for it otherwise you may be better off using them for something else like treasures.

I don't know, 1280 -> 2695 seems pretty significant to me, why do peple say minimal?

I am playing this game against better judgement where there are coin requirments for what I consider to be basic or mainstream components of game play, in this case resource upgrades. I understand the game has to be paid for, and I am fine with a model where people in a hurry can choose to pay what is really a disportionate amount. As opposed to just a flat fee for everyone (which would be fine by me, but too late for that now). But having resource upgrades coin only, no option for in game currenty at all, really bothers me.

Look at it this way, a realy good iphone app is what $10, that would be high really. Let's say double it to $20 considering this game requires ongoing server support. (of course in this case everyone pays...)

To upgrade all resources in just one city is 900 x 4 coins = approx $300. WOW.

I use the word "minimal" in comparison to the amount of resource gained between using resources alone and coins. Coins are much more valuable and one would think the output would reflect the cost. Yes the out put from 15 to 20 is noticable, however at the cost of 900 coins it seems a bit small. Increasing the output would only help Haypi sell more coins as it gives a big incentive to upgrade past 15.

Well i agree with that but. Then i would not upgrade and only use the coins for buying crops rader then upgrading. 900 coins= 1,800,000 crop

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