I have never photographed a pre-school but my son's pre-school sends home packages twice a year. The price in my opinion is crazy. It's 12.00 a sheet and we don't get anything free. As a parent I'd appreciate a lower price to order. Maybe you'd get more business that way and end up making a good amount. They send home a month ahead of time three background choices. I select which one so I know what to dress him in then I get the photos about 2 weeks later. I wish they had online ordering because printing out all the poses is a waste to me. Just my thoughts.
You think $12 a sheet and nothing free is crazy? You would probably faint to see what some people on here charge for a single sheet then.

I believe $10 is minimum what anyone charges for a sheet, usually much more.
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!
Figure out what your expenses are, equpment, software, prints, gas, figure in the time you will be there photographing, the time required to process the images to look their best, the time making the proof packages to send home with the kids, if you have a portable backdrop, its cost and time to setup, the time dealing with the lab, and gas again to drop the pictures off. Then go from there.

But also consider what your market can bear. If the average income is pretty low, then you probably cant charge top dollar. Unless its a private school.
Just for comparison, im in a pretty rural area, the average income is pretty low compared to the national one. For the hosted event I just did, I charged the following. $20 for one sheet, $35 for 3 sheets, $60 for 6 sheets and $85 for 9 sheets. And I limited each sheet to be one pose. I dont believe anyone complained about the prices or about the one per sheet rule. Thankfully most of the parents purchased the $60 and $85 packages, with only a couple buying the $35 one. But they did have more than one pose to choose from. I believe school pictures only give you one pose? You could try doing a couple more, but that would incrase your time drastically.
I did my home Church directory before that, and I offered a special price since they are like family. I cut the prices down 33%, and I dont believe one person complained about the prices. But some were confused why I couldnt offer multiple pictures per sheet, trying to get the most out of their money. Could be coincidence, or it could be the lower prices they expect more?
Also, dont be afraid to offer extra things, never know what they may buy. selecitve color, black and white, sepia, collages, canvas, etc.