Being Cheap? or Uncompassionate?

A couple weekends ago I had a garage sale with all the proceeds going to World Vision to help feed the starving in the Horn of Africa. It amazed me that people were still cheap and not willing to give a little more. I understand that garage sales are meant to find deals but if someone is giving ALL proceeds to feed the hungry wouldn't you be willing to give a little extra? Why are we so immune to other's suffering? I know we all have different passions and concerns and that's the way it should be BUT still you can't give a little extra. You can't pay $3 instead of a $1.50 or $4 instead of $1? One guy wanted his $.50 back! It's not like I was asking someone to give $20. Am I being totally silly about this?