The cost of money

I went to an ATM in Belfast recently and got 100 pounds out of my bank account in the U.S. and 100 pounds out of my U.S. credit union account. I balanced my checkbook yesterday and saw that the bank charged me $153.74 for that transaction vs. $150.13 for the credit union. I expected the credit union to be lower but I had no idea by what spread.
If I ever get on top of Queen's deadlines (no progress today due to a series of trades people), I'll move the bank account to the credit union.
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