Ben, several dealers in the southeastern PA area are quoting approximately $9100-$9500 for the ZD21(this is without the ROPS.) One dealer has quoted me approximately $250. additional for the ROPS on the new units. Hope that helps.
Note that there is a ZD18, ZD18<font color=red>F</font color=red>, ZD21, ZD21<font color=red>F</font color=red>. The F versions come with ROPS. I was just at the dealer today and they were quoting the ROPS as an adder for $400 so I assume you can add it to an existing unit.
OK. From reading their flier they sent me, I understood that they all were coming standard with the ROPS. If they are still offering them without the ROPS that makes me feel a little better.