Is it normal to be charged a bond in amateur musicals?

I've lost count of how many shows I have personally been in but in all these shows I reckon that I could count on the one hand how many cast members have pulled out!! I am wondering what is it that is causing these cast members to withdraw discounting the accepted reasons? AND enough of them withdrawing to have to hold others and future others to ransom! One question Catfang, is the $200.00 held in trust then returned at the end of the season OR spent hoping that enough money is made to pay them back? I must admit that this astounds me!! In WA I have heard of the odd show charging people to audition which is also a disgrace. Alex PS CHESS is an awesome show that I have proudly performed in and we had a sensational cast (A number of them are now doing this professionally).