If you are thinking about having someone driving around to photograph everything frequently, yes. But a couple of cars outfitted like the Google Street View cars, each given a section of the city to drive every other month or so is very feasible. You could also put cameras on any public transit vehicles to keep photos coming in from vehicles that are already being operated by city funds.
It wouldn't be a daily thing. Maybe once every other year at most. The cost would be minimal to the government to hire a few contractors for a one-day thing.
Why not? If you are looking at least 10k/house in taxes, it's very efficient to have a full time staff to check out the recently flipped (well...) MLG houses.