To be fair, the supply of useful consumables does seem quite limited. I've never got my hands on more than two lots of wyvern poison or 3-4 oils of sharpness, and I am tediously thorough, trading with even minor NPCs, searching out every treasure chest, etc. (Potions of invisibility and speed are more plentiful - maybe 15-20 of each if you search exhaustively - but they're much less impactful.) It means you can't just cheese your way through every encounter and have to conserve your resources for the truly hard battles.
