Repeating Calc Using 1 Repetition from another rf

[BigRobA]

How do I get each repetition in a repeating calculation field to reference a specific repetition from another repeating field?

The following just returns a blank field and it won't let me stick Extend in the GetRepetition part in any way:

If(Extend(Number of Colors) = 1, GetRepetition(One Color Price, 5),0)

This is pretty simplified from what I'm trying to do but I've isolated the problem as being the GetRepetition(One Color Price, 5) part. How do I need to change it so it works in a repeating calculation field?