there is also a lot of crystals. not just 20. You can get like 130 of them and sell them to the blacksmith in the camp. they sell for I think 4 dollers each. so collect as much as you can.
if you can't find it on your own once you've spoken with the medicine man person go to your map in the select menu and it will show a new dot that says the crystal mines it's easy to get twenty without much work so if you want to be a chicken and just run in and grab twenty from the first few chambers and save your health you can but if you're low on cash there are 125 crystals in the mines total but keep in mind you can only sell them in the andrellian isles so don't forget to rid yourself of them before you leave or you can save them for markers to tell you whether you've been somewhere before by dropping them every so often