Finding Change Types between tables

Hello,

I have two different data sets. One is previous week of sales data, while the other is current week of sales data. Between these weeks of sales data, there may be changes made to the revenue of a sale, or it's probability of occuring. I am trying to create a measure that tracks these changes, but I am struggling with finding the right DAX functions for the job. 

Using these two tables, I have created a table that contaings the sales IDs that have been changed (call this ChangesData) in either revenue or sales probability, along with their new revenue, and their new sales probability. I also have a table containing the old data that we are updating from (call this OldData), which contains the same fields. I would like to create a measure that track the specific changes to each ID (whether it be sales probability or sales revenue) between these two tables, resulting in something that looks like the table below. Keep in mind that the Probability column is a categorical variable which levels are (50%, 70%, and 100%).