Rome and Florence are best in the off-season. You get the Colosseum and the Uffizi without the summer crowds or the heavy heat. In November or March, the air is crisp, the pasta is just as good, and the flights are cheaper.
A typical trip for two runs about $3800. We can break that cost into smaller monthly chunks. If you use the Citi Simplicity® Credit Card (Citi), you get 0% for 18 months on purchases and balance transfers from date of account opening.
The 0% rate is a grace period, not a discount. If you still have a balance after the 18 months, the standard interest rate kicks in on the remaining amount. Pay it off before the clock runs out to keep the trip interest-free.