Produce a combination of all permutations for 4 groups of data with 4 unique values contained

Question

I'm trying to calculate sums of all unique combination for a set of data. 4 groups of data, with 4 unique values. E.g. Concrete 1 (CT1), Concrete 2 (CT2), Concrete 3 (CT3), Concrete 4 (CT4)/ Timber 1,2,3,4 (T1,T2,T3,T4)/ Steel 1,2,3,4 (S1,S2,S3,S4)/ Carbon 1,2,3,4 (CR1,CR2,CR3,CR4). An example of unique combination = CT1,T1,S1,CR1 / CT1,T1,S1,CR2 / CT1,T1,S1,CR3 / CT1,T1,S1,CR4.

I believe there are 390625 unique combinations. I'd like to work out the sum of all of these unique values. I've attached an image to try and illustrate what I'm looking for.

How should I go about this?Combination Diagram Example

Using excel I was able to do simple summations but only for 2 way sets. I.e. CT1,T1. CT1, T2. CT1, T3. CT1, T4. etc.

Not 4 by 4.