Hi,
Are you use your telescopes for visual or photographing?
If doing photo I will say there is a must to have a focus motor. Since I built my focus equipment I reach much better focus. And I also have found how temperture sensitive it is. I have it temperature regulated and it works.
Here is my little focus projekt:
http://astrofriend.eu/astronomy/proj...tor-focus.html
When I bought it it cost abot 160 Euro, I have the middle motor. It's more expensive today.
A lot of people built their own controller and maybe can save money. Stepper motors are cheap at Ebay.
Lars