Drupal Commerce: How to manage different payments (a total amount can be pay in different shares and the user can choose in how many shares) I´ve just installed the Drupal Commerce module in D7, and after watching the video tutorials I think it´s fairly complex, maybe it´s just too much for what I want to do.

I´ve this site where we only sell e-courses. Each course has a total cost, but people can pay just a small part to get enrolled.
The problem is that people have a minimum to pay, but they can pay a bit more if they want, so even is the total price is fixed, I get people to pay different amounts of money each time.

In example:

Course A costs 1000.

To get enrolled you have to pay 100, and then 100 per month (those are recurring payments).

Now, one student can pay 200 when he enrolls, and then after that he can, if he wants, to pay in 200 shares instead of 100 shares. Maybe he can pay 300 to get enrolled and then shares of 100 each.

How may I manage that with Drupal Commerce? Is it possible?

Thanks!
There is Commerce Installments


  Commerce Installments allows you to create installment payments for
  products in a Drupal Commerce store.


Make sure you read Issues for Commerce Installments