Put 70-100 points into Biology. Keep a stack of crafting components in your stash. Learn to make Super Health Drinks and Crawler Poison.
Early game, pick every mushroom. Pick every root. Craft Antidotes . Antidotes cost basically nothing to make (a few common plants), but they sell for a fortune to doctors. You can clean out a vendor’s entire ammo stash just by selling them the cure for a poison they don’t even have. You don't need to max Biology. You don't need to be a Biologist instead of a Sniper. You just need to respect it. biology underrail
But let me stop you right there.
Here is why Biology is the most underrated skill in the game. Yes, you can buy healing injectors from a vendor. You can also pay 100 charons for a bottle of dirty water. Don't be that guy. Put 70-100 points into Biology