Here  is  a  spreadsheet  tool  with  tables  that  shows  the  cost  of  building  upgrades  from  lvl 36-40  and  will  allow  you  to  select  specific  buildings  to  plan  your  upgrades.  

https://docs.google.com/spreadsheets/d/1c8NTTl7ob9PaO63d0opu68kzNV7sf_VwLSxYSe2L6LY/edit

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Tables  of  the  new  secret  knowledge  tree  bonuses:

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