Notaries public have a lot of latitude in determining the fees they set. Some banks require an employee or two in their branch to get a notarial license (and the banks themselves pay for employees renewal of latter's notarial commissions) because they want to be able to give notarial services free to bank customers.
Whereas, some employee/s of banks happen to be notaries public and the bank has nothing to do with this and so these employees set their own fees. This is the reason why some of us get free notarization and some need to pay to get these done.
That makes sense why some places charge while others don't. I also heard that rules are changing in some states (i think i read that on this forum a while back).