I know it would be more economical to send a box with wheels & an antenna, but if anything goes wrong, it may not be able to fix it's self. Game over.
A manned mission would cost much more but may have a better chance of being successful. One reason for this is if you're going to send humans, you have to have the tech to get them there & back alive. If something goes wrong, a person may be able to fix it, or alter it & be able to continue the mission.