What does "Pay Off Remaining Balance" mean?

All of your Rent-to-Own plans are located here: https://splice.com/profile/billing

If you click on Manage plan you'll see the plan page for that specific plugin/DAW.

You can see how months are left in your Rent-to-Own subscription and the balance remaining. 

If you wish to skip the Rent-to-Own monthly payment plan and want to purchase the plugin/DAW in full you can select Pay remaining balance.

This generates a lifetime license for that plugin/DAW and you would then own the plugin after activation.

Please note that all Rent-to-Own payments are non-refundable, including paying off the remaining balance.