Arn't you forgetting the cost of the washer Mick...lol
What does the E-Z focus do...dont you have a micro-focuser.....
I have seen the thick washer that just goes over the focuser knob to give you a little more control......but I just leave it up to the micro-focuser.
http://www.digitalastronomy.com/html...knob_lx200.asp