Is there a way to get / reference a specific table field / value in a measure

Hi RubySmith 
I created the same scenario. I am getting the result that you want. please do the following steps.

Step1-) Create 2 seperate table like in your case 

 steps2 ) create relationship between 2 tables based on license.

Add cost to the Main table:

step3) create measure under Main table for user count.

Step 4) create the following measure  (It finds Min value in annual cost and multiple with user count like(2*10)

 

Min license =

var M= CALCULATE(MIN('Main(cost)'[Annual Cost]),ALLSELECTED('Main (1)'[Company]))

var N= [Count(user)]*M

Return N

 

step5) create new measure for Annua cost saving

 

Annual cost saving = sum('Main(cost)'[Annual Cost])- [Min license]

I hope I answered your question please give kudos and accept it as a solution!
Thanks