Second hand gear
Buying second hand gear is a cheap way to start kitesurfing but be careful what you buy. When you are learning kitesurfing it can be tough on your kite as you will crash it into the water occasionally, sometimes hard. If you buy good second hand gear it will serve you well, and you can upgrade the latest and greatest kit after your first year if you want too. You can also sometimes score last year's kite model for a significant discount just when the new model comes out.
You can buy a complete set of secondhand gear (board, kite + bar, harness), depending on condition, anywhere from A$600 to A$2000. (Price ranges for new gear are: Kite: A$900 to A$2000, Board: A$750 to A$1300, Harness: A$120 to A$250.
You won't worry too much about damaging your kite if you crash it while learning
You don't a need high performance kite or board; its better to go for gear that is easier to use while learning.
Gear that has been used a lot may be worn out and fail. Kite fabric and lines weaken with UV exposure so try to avoid buying something that is obviously very worn or faded.
Second hand kites will often have minor and sometimes major repairs. Repairs can be another potential point of failure, but are usually OK if done well.
Harnesses wear out with use too - buckles and straps can fail. Check for worn or frayed straps, particularly around the bar attachments.
Boards can de-laminate and break - but its not too hard to see the condition of the board on inspection
Buying gear unseen over the Internet entails more risk as you can't inspect it well. The price may be good, but the quality may not be what you expect.
It may be safer to buy second hand gear from an experienced kitesurfing friend or a kitesurfing shop
Where to get second hand kitesurfing gear
Some options for second hand gear are:
Local kiteboarding shop - they can also provide advice on what is best for your skill level.
Local online kitesurfing forum / website (e.g. Seabreeze in Australia).
Kitesurfing friends. Someone may have some old gear they are no longer using.
Ebay. You need to what type of gear to get, and you have to rely on photos & text for gear condition.