Efficiency

Level 5 of the Dungeon
(0, 0, D:5)
  11 gold pieces
(6, -5, D:5)
  15 arrows
(9, -15, D:5)
  a +0 helmet

Level 6 of the Dungeon
(0, 0, D:6)
  a +0 robe
(3, 0, D:6)
  22 stones
(9, -27, D:6)
  9 gold pieces
(17, -19, D:6)
  a scroll of teleportation
(23, 8, D:6)
  an adder corpse

Level 7 of the Dungeon
(0, 0, D:7)
  a hound corpse
(6, -4, D:7)
  a potion of magic
(11, 1, D:7)
  2 gold pieces