Amanda
As has been mentioned an 8" dob is very often the ideal beginners scope having adequate aperture, easy to setup and transport, easy to use and inexpensive.
Personally I wouldn't recommend buying from ebay unless you have done a lot of research or knowledge. You may luck out and get a good scope but often times not!
Best bet is to visit a specialist shop. Scopes are often sold in camera shops and Aust Geographic stores but the staff have little practical knowledge and will likely confuse more than guide. A good store I can recommend is Bintel in Stdney (see
http://www.bintel.com.au/?utm_source...paign=branding )
If you visit there I am sure the staff will be able to help you and at least you can see some scopes and get an idea of their size.
Malcolm