The Mine is the fifteenth upgrade, which builds a Mine that produces wagons with ore, which give boost to the money machine. It caused before version 1.04 the one critical Bug.

Level Cost Effect
1 100K
2 300K
3 900K
4 2,7M
5 8,1M
6 24,3M
7 72,9M
8 218M
9 656M
10 1,96B