I have been contacted to do preschool prints for next Fall and I have no idea what to charge? 80-90 students, 4 classes. Obviously each students get a free 5x7 class photo, then I do individual shots and charge for them. Packages? I think the last person did $10 a sheet (8x10 or 2-5x7...) I think I would do better if I did lets say 3 package options? Any help or input would be great! Thanks in advance!