In case you take two or more courses you might be eligible for a combination discount. Please check the website to see whether the course offers a combination discount. You can recognize the courses that participate in the combination discount by the logo on the course page. Please note that every course you want to combine needs to have that logo on their page!
The discount is calculated each time you choose "pay now" in your account since it may change after you have applied for an extra course or cancelled one of the courses that you already applied for. Therefore, the discount is not visible in the overview of your pending applications.
Other discounts (if available) are registered by the course leader manually. More information about discounts can be found on the course page and on this discount page.