Here are the official game rules for exiting from Intuit's death grip.  I didn't notice a $300 early termination fee.  Are you sure they aren't just nicking you the fast path fee so that you will have access to your program after you depart to greener pastures?

https://proconnect.intuit.com/support/en-us/help-article/intuit-refunds/proseries-cancellation-refun...