It is interesting. I would have two areas it might come from. First is Arak, second is Northwest persian Khoy. Arak is more likely. Mohajeran is later, this rug is older. Late Ziegler production would be my definiton: Design is not typical for early Ziegler, the first two borders and the corners of the inner field are atypical - this is an argument for foreign influences (English). The back side picture shows knots that look like Mahal or Viss. I would come to Ziegler Mahal, ca. 1890 - 1900. OK - condition is heavy worn, but this is not a rug you put in a dining room - it is a rather interesting collectors rug. I would say price is ok.
Knot looks symmetrical, which would be typical for this rug type. Colors probably natural, at least most likely. Wool in this type of rug would most likely be machine spun.