We had to go to Rome for a meeting a few years ago. That in itself was a shambles but another story. They booked us somewhere in the suburbs and it cost us a fortune in taxis. Public transport is not great so I would suggest you try and find somewhere near the spanish steps and then you can walk everywhere. Like all large cities, especially capital cities, Rome is expensive and you can't get away from that. The rate of the currency exchange doesn't help either.