Efficiency

Level 5 of the Dungeon
(0, 0, D:5)
  a +0 ring mail
(1, 4, D:5)
  16 stones

Level 6 of the Dungeon
(0, 0, D:6)
  10 gold pieces
(5, -1, D:6)
  13 arrows
(15, -5, D:6)
  a potion of berserk rage