I went to a Chiller convention and paid each cast member of the original Last House On The Left $20 apiece for them to autograph a poster, I thought it a bit hefty, but a worthwhile exchange for a somewhat under-appreciated film. When I ran out of 20's, the guy who played the chainsaw wielding dad, signed it anyway.
William Shatner, on the other hand, wanted $495 for 15 mins with him at Comic Con. I just laughed and thought, "What a S'pange!" But yeah, there was a line to see him. So I laughed again.