Efficiency

Level 5 of the Dungeon
(0, 0, D:5)
  a potion of flight

Level 6 of the Dungeon
(3, 12, D:6)
  9 stones
(11, 16, D:6)
  26 sling bullets
(22, 8, D:6)
  22 arrows
(23, 2, D:6)
  a scroll of blinking
(23, 8, D:6)
  14 gold pieces
(25, 15, D:6)
  a book of Displacement