It seems that Storm8 reduce the material demand.
expand 3


expand 20
Before:20- 20 Blue Prints, 1,040,000 coins, 12 hammers, 9 Shovels
Now: 10 Blue Prints, 600,000 coins, 5 hammers, 4 Shovels


expand 21
Before: 21- 21 Blue Prints, 1,100,000 coins, 40 nails, 10 shovels
Now: 10 Blue Prints, 600,000 coins, 14 nails, 3 Shovels