Efficiency

Level 4 of the Dungeon
(0, 0, D:4)
  a potion of mutation

Level 5 of the Dungeon
(0, 0, D:5)
  15 gold pieces
(12, 2, D:5)
  a +0 dagger
(40, -8, D:5)
  14 gold pieces

Level 6 of the Dungeon
(0, 0, D:6)
  a +0 rapier