I'm not sure a significant raise in meter fees is required. If the sensors are tied in with the meters themselves (letting you pay for it over your phone and whatnot), then a lot of the work for the city's parking enforcement is gone. All that would be required is to keep track of expired meters with cars still parked there, and any cars parked while parking is not allowed.
Although that will probably mean that a lot of people might lose their jobs, it means that the gov in turn saves money on gas|CNG|power for the cars, and possibly get more money from parking tickets.