This can be an impossible achievement! The fact you lose a sizable portion of the gold you're carrying when you die combined with the finite amounts of materials in the world, too many "valuable" deaths can make you not have enough total gold to unlock / afford all the upgrades in the game. Play very cautiously in new areas, and if you die near when you last saved (entering a mine or visiting the surface automatically saves the game), don't be afraid to "dashboard" before respawning to avoid losing that money.
You won't be able to get this until near the end of the game as you will need an incredible amount of gold. I had to mine nearly the entire world since I died nearly a dozen times, again why you should be careful of unnecessary deaths. These are the items that you will need to purchase all upgrades from all the vendors to count towards this trophy:
- Pickaxe
- Drill
- Steam Punch
- Armor
- Water Tank
- Lantern