Flat Rate Product With Qty Restrictions

I checked the forum and manual to see how best to accomplish the following setup for a client recital coming up.

We'd like to offer a flat rate charge of $75 per student that includes three images and any additional images are at a discounted rate of $15. per image. We need to ensure people purchase the flat rate option before being able to purchase additional images. 

We're also looking to have the parents specify the number of students to ensure we charge them appropriately. I realize this isn't a technical issue so any guidance you can provide is absolutely appreciated and hopefully I'll be able to return the gesture. 

One last thing, I've created a new page, enabled pre-register/order form, new product, and price list. The test page can be accessed https://250116040701.proofingphotos.com/ada-recita...  

You would have to use the pre-registration  + Pre-ordering. 

You can charge a registration fee, but that doesn't include products.

So in the pre-ordering, you would need to make it required.

And in your price list for your pre-order, include a package that has to be selected. It can be in a required product group and once a package is selected from the required product group they can have the option to purchase additional products.

Using this method will also make a parent select a package for each child. 

https://www.picturespro.com/sytist-manual/photo-pr...