At the moment, it seems the two main options are a tracking platform or EQ mount.
A new tracking platform has recently become available at Bintel for about $1,050 (I think). These platforms are not that available in Australia, but can be imported from overseas - but customs seems to be quite costly!
The other option is an EQ mount... and the cost depends on the size of your dob. An eq5 can just handle an 8" newtonian (I believe?) and an eq6 (costing about $1,500) is required for anything larger. I'm not a real expert in the actual specs of these, so I might be a little off
I have also seen many cool ideas for improved manual dob tracking, such as the dob wedge that was posted in a thread a short while ago. I wouldn't mind having a go at that myself if I wasnt useless at woodwork
I hope this is useful to you! Many dobbers are also interested in tracking (myself included
)