Not sure how to word that, but is there a PayPal module that can be used to charge a fee for a specific download?
Not a fee for the whole course, but for a specific resource download for example.
A student signs up for the course. free.
The student needs to download a booklet in PDF format that has been prepared for example with the work module. That needs to be paid for first, so the student pays via PayPal, and the download progresses.
Other students may or may not need that resource, so they either pay or don't pay,
Or, let me explain another way.
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Course 1. Mechanics. (Free enrolement)
Reading 1. Download ($2.50 PayPal) Your download will start when payment is processed.
Reading 2. Link. (free)
Assessment 1. (Fee. $2.50 PayPal) Your assessment page will open when payment is processed.
..... and so on and so on.
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Thanks
Moodle 2.2.3+
Robert