Understanding the domain pricing fields

[nuffsaid]

Hello Folks.

I need a bit of help understanding the domain extension fields for 2 fields.

Say for example,  if i put a price for 2 years for registering a domain name, the Redemption field, am I supposed to double it as well or its the same price going down since i believe you can only redeem a domain once?

And also the "Before Promo" fields, what is it used for and how do I properly use it?

Here is an image of the sections i need help understanding.