>So the question is: do the members then HAVE to pay the audiotour price
in order to enter the exhibition OR do they have
the option not to take the audiotour?  The point is that the paying
customer might opt not to take the audiotour and thus expect some sort of
discounted admission on the theory that the audiotour has a cost.  Any
real life experience with this?

With our last large exhibition, we included an audio tour in the price of
the ticket.   We allowed our members to call in advance and get two free
admissions which included free audio tours.    If anyone doesn't want a
tour, they don't have to take it, but they don't get a discount.   We had
notebooks available with the tour script for hearing-impaired visitors.

P. Fox
TN State Museum