Leveling
In some point that game upgrades gets usles, like that idle pump. You upgrade it but tank capacity wont change so it fills full about 1min and have just 1mil galons but you can get from mine for about 2bilions from one pit. And pick axe upgrades un one point won’t change mining speed too so basically you can upgrade your backpack tank volume and if you do so then mining pits get bigger and you can get maximum money from it.