some drill rigs are semiautonomous, with GPS. The control systems were priced around $120k the last time I looked about 10 years ago. Any HN'ers want to disrupt this? I know some drillers out this way.
If you wanted to disrupt this, I suspect you don't want to make it cheaper (the mining companies have plenty of money), but to do a better job somehow.
(Where are you?)
This is called "Precision agriculture". Tractors and equipment enabled with this can throw the precise amount of fertilizer/seeds at specific points. Probably quite a hot topic in farming... Go to any farming show and you will see this.