Buying a second hand bike is like buying anything second hand, it will have wear and tear and will vary in condition depending on the previous owner. In all cases it pays to inspect the bike and see for yourself. However if you are buying from a seller interstate use a friend in that state if you have one to inspect for you or, have the seller take a detailed video for you showing you in more detail the condition of the bike, even using face time so you can ask the seller real time about any concerns you have.
The million dollar question ? what bike best suits me well everyone has an opinion on this question and it will vary from what they are trying to sell you on, is it down tube length? or is it top tube length. To try and simplify this the most important aspect in my opinion is the top tube length ? why you ask.. simple if you are to stretched you will never be able to ride safe and comfortable that is the very short answer that does not mean you are a person that is 183cm tall and ride a 49cm bike, it means check the brand you are buying and the geometry details are always available on line and double check the frame that is suited to you height, the attention to the top tube measurement is key as many modern bikes now place emphasis on seat tube and then you discover you have upsized yourself and will forever me un comfortable so every in doubt one size smaller maybe the better option a longer head stem and a slightly higher seat is how all completive cyclists have their bikes .. WHY … its gives you more fitting options remember the bike must fit you not you fit the bike…
Buying a bike from interstate can be tricky and it will require the cooperation from the seller to work with you to organise packing and freighting. However most local bike shops will pack bikes into cardboard bike box’s most shops have a surplus of box’s that suit nearly all size bike. the cost for packing a bike ready for shipment will vary and it pays to make contact with a local shop close to the sellers home, most bike owners have a favourite bike shop and can readily answer this equation for you. As for shipping some bike shops are happy for the freight company to collect from their shop as long as it does not stay in the shop longer than a few days. There are many companies now that specialise in bike shipping an a quick google search will show some very cost effective options. The most important part is that the seller is willing to work with you to get the packing and shipping organised so before you fall in love with you new ” second hand” ride ask this early in the discussions.