Efficiency

Level 5 of the Dungeon
(0, 0, D:5)
  13 gold pieces
(25, 15, D:5)
  15 stones

Level 6 of the Dungeon
(0, 0, D:6)
  an adder corpse
(16, -1, D:6)
  16 arrows

Level 7 of the Dungeon
(0, 0, D:7)
  a +0 leather armour