One person suggested a Dragon could carry all coins back to his/her lair in a pack--I kind of reject this out of hand because many dragons are just so huge that I doubt with their giant claws they can ably dangle a tiny (to them) humanoid backpack. Kinda like the opposite problem of a halfling trying to wield a Hill Giant's club.
Someone else suggested Dragons are intelligent enough to make their own packs. My first reaction to this is wouldn't it make the Dragon look rather comical? Aren't Dragons fiercely proud? Do they really wanna look like a college dweeb on his way to Organic Chemistry class? Do they want to look like they've just returned from a trip to REI, Urban Outfitters or the outlet mall?