Cheap ebay focussing rails ?

[*gold*]

I am very keen to try focus stacking, I have seen the rails on eBay from as.little as £11.99 posted.
Are these any good to start out with or are they likely to put me off before I get going ?
I would prefer answers from experience but am grateful of any help,
Many thanks
Cliff

 

[stormcrow]

I bought one of these a few weeks ago and I am more than happy with it.
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=370230905990&ssPageName=ADME:L:OC:GB:3160
Its construction is metal; it is heavy and feels solidly built. The action of the rail is smooth but this is the only rail I have used so I have nothing to compare it with, I did some photos where I advanced the rail approx. 1mm each time and that was no problem at all.
The only complaint I have is that it is a little fiddly to screw the fastener to the camera but that is a minor complaint.
It comes from Hong Kong and I think it took about 7-8 to get here which isn’t too bad seeing as delivery is free.