Hi Jill: My wife and I are great fans of Osprey packs, but there are some other Ospreys that are cheaper and lighter than those you mention. The Lumina / Levity 45 that you refer to is indeed under 2 pounds, but it is very expensive — retails for $250. The smallest Exos pack (38 liters) weighs 2.5 lbs, and costs $180 retail. However, Osprey offers several other packs in the 30 liter range (which is all you need on the Camino) that are cheaper and lighter. These include the Skarab 30 (1.5 lbs / $130); the Skimmer 28 (women’s only - 1.7 lbs. / $130); Hikelite 32 (1.75 lbs. / $55 - $110); Talon 33 (1.9 lbs. / $140; and the Tempest 30 (for women only — 1.8 lbs. / $130).
I carry the Talon 33 and my wife carries the Skimmer 28, and we are both happy with these.