Vienna is best in late winter or early spring, when the city feels quiet and the coffee houses are perfect for escaping the chill. You can spend your days listening to world-class orchestras and your afternoons nursing a melange in a velvet-seated cafe without the summer crowds.
To manage the $3100 cost, you could use the Citi Simplicity® Credit Card, which offers 0% for 18 months on purchases and balance transfers from date of account opening. This lets you break the trip cost into smaller, manageable chunks rather than paying it all at once.
The 18-month window is a deadline, not a gift. If you still have a balance once those 18 months are up, the bank will start charging interest on whatever you owe.