Mercury is among the least explored planets, despite its vicinity to Earth. Just two probes have been sent to Mercury, a third one is underway and no probe landed softly on Mercury so far, Messenger just crashed onto the planet. The poles of Mercury provide for a good environment to operate a probe or rover in (and eventually for a human base).
The only celestial bodies rovers have been sent to so far are Mars (by America) and the Moon (by the Soviet Union and China). A Venus rover (Zephyr) is in concept. Why aren't there proposals on sending rovers to a planet whose surface is still unexplored from the ground? What would be any obstacles for such probe, except for being careful to not let it fall into the Sun?