How to calculate the difference between values with columns of different codes

Hi,

I need help to calculate the difference in the price of each procedure code in two tables. Each table is from different organizations (the one on the right is my organization, and the one on the left is the other one), so the procedure codes are not all in the same order, and there are some codes that might be in one that are not in the other. I would just need to calculate the difference in price in the column named Fee and for the procedures that are in both tables.

The example I added has just one mismatch, but the original has more mismatches between the order of procedure codes due to missing codes, although I tried to sort it the best possible.

Thanks for any help