The first and foremost thing to remember when buying a motorcycle is to make sure that the seller has the appropriate road worthy and safety certificates. If these are not supplied with your purchase then dont become involved and they should be supplied at the sellers cost. Remember "buyer beware". Before bidding ask the seller if an inspection is welcome before the auction ends - if they have nothing to hide then an inspection will be welcome even if you have no intention of carrying it out!
Also make sure that the photos you see are of the bike you will purchase. Some sellers sell a very similar type of bike numerous times and use the same pictures.
Check on the legal requirements of operating a scooter - if it is over 50cc then you will need a motorbike license. Queensland is the only state that allows you to ride a 50cc bike with just an open car license.
When you go to collect your new purchase print a copy of the whole of the advertisement layed out on ebay. Try to arrange a payment on pickup so that you can make sure that you are receiving the bike you have bid on. Once you have the bike in your sight do not leave it as switches can be made (either to parts or to the actual bike).
Look for the odometer reading and make sure it is accurate. You can do this by looking at the age of the bike and reasonably work out the mileage used over the age of the bike. Remember if it seems low then it probably is and the odometer may have been disconnected or a new one installed. For your information Australia Post dispose of their bikes between 28000km and 30000km so if there is a bike that says it is from australia post and has low mileage you will know that the odometer has been changed.
Make sure that the bike is started in your presence and listen for any "rattling sounds" that are not usual in the operation. Check that all the lights and indicators are in good working order and that the head light turns on as soon as the ignition starts. Look for any signs of oil leaks as this can lead to a problem that is ongoing and costly. Finally, ask the owner to take the bike for a short ride up and down the street they live on so you can hear and see how the bike runs. If the seller shy's away from giving a demonstration then you can well assume there may be a problem. It is illegal for two people to be on a postie bike - there can be no pillion passenger and high speeds on a normal postie bike are just not authentic - the highest speed you can achieve with a normal postie bike is 75-80 - the only way for this bike to go faster is to change the sprocket and gears - so be wary of anyone who tells you that a postie bike can go any faster than this.
These are a great bike and very dependable - not a racing bike - but if you want an economical and dependable bike then make sure of your facts before you buy - ask some of the questions above to the person selling the bike - their answers will tell you just how much they know about the Honda CT110.