If you dive into the program memory, there's GameHistoryData's miningCostRate and miningSpeedScale variables, which are single precision floats. These are the values I've verified:
| Level Researched | miningCostRate | miningSpeedScale |
|---|---|---|
| None researched | 1.0 | 1.0 |
| 1 | 0.93999999761581 | 1.1000000238419 |
| 2 | 0.88359999656677 | 1.2000000476837 |
| 5 | 0.73390400409698 | 1.5000001192093 |
| 6 | 0.68986976146698 | 1.6000001430511 |
--76561198010365021 (talk) 23:58, 30 March 2021 (UTC)