Steve's General Store is a store where you can buy upgrades. It is located near Dave's Refinery.
When you buy something, the price will continue to grow until you reach maximum. You can buy gamepasses (some) in the store.
Things you can upgrade Edit
You can upgrade the mining speed for dirt, stone, and ores. Later on, you can upgrade the speed for obsidian and granite (these upgrades tend to cost thousands of dollars).