Add ability to change the default pricing on the Course Overview page

Use case: I have a membership that includes all my courses for a super low price and want to emphasise what good value that is. You can also buy the courses separately and choose a pay in full or instalment option. I've turned on course upgrades and the Course Overview page defaults to the lowest instalment price.

There are 2 issues:

a) this doesn't show the great value of the membership and

b) doesn't even show the true instalment price as it only shows £99/mo not £99 for 3 months.

Adding a button to allow us to select the default pricing would get around both of these issues!