Rome is an inexpensive city compared to most Western capitals and there are plenty of ways to save. The biggest expenses are getting to and staying in Rome and both fluctuate according to the time of year. The more people want to visit the higher prices for plane tickets and accommodation will be. You can therefore save considerably by planning a trip in May or September rather than over the summer or religious holidays.
Of course not everyone can choose when to travel and there are other ways to save even if you must arrive in August. All Roman museums and monuments provide discounts for children under 12, young adults between 18-25 and seniors over 65. Benefits vary from 50% off to free and are clearly indicated at ticket offices. Museums throughout the city (including the Colosseum) are also free on the first Sunday of every month and the Vatican Museums are free on the last Sunday of the month.
Eating out is one of the greatest pleasures of visiting Rome and good food is not expensive. Bars in the historic center however do charge one price for sitting down and another for eating or drinking at the counter. You’ll notice most Italians enjoy their coffee quickly while standing while visitors tend to sit and sip their cappuccinos at the tables outside.

Restaurants offer plenty of pre-fixe menus and if you don’t think you can finish off an entire bottle of wine you can always ask for a half or quarter carafe. Unless you are a connoisseur you can’t go wrong with the house wine (vino della casa) for both price and quality. Avoid restaurants near major monuments and search for smaller osteria where locals eat and first courses rarely exceed €10. You can also prepare your very own picnic with products from markets, specialty shops or mini markets and enjoy it on a quiet square or park bench.
Getting around Rome is inexpensive although taxis are pricey and can be difficult to find. There are plenty of buses and trams in the center and they provide an authentic experience you can’t get from the back of a cab. Single tickets are cheap (€1.50) but if you plan on using them a lot a daily (€7) or three day pass (€18) is useful. Children under ten always travel for free.

The best things in Rome are free and there is never a charge for drinking from fountain, getting lost in the back streets of Trastevere or admiring the view of Rome from the Spanish Steps.
MORE:
Italian Economics: Prices of everyday things
Travel Card Options