I once used, in a AD&D campaign, the loss of beer, ale and mead ingredients for a multi world and plane campaign. None of the players cared that food in their area had become scarce or that the folks at the source of ingredients where dying of multiple diseases, but raise the price of ale and no mead. I couldn't get them to the area fast enough.
And just to add a bit of sauce I added that the price of
beans had gone up a hundred fold. The groups Monk arrived 2 days before the others!
Now that's what I call motivation.