You need to weigh up the options.
Brand new you get the big advantage of retail service, warranty etc. But you will pay more for something that you may destroy depending on your ability.
Or buy Second hand and risk a crap buy with no comeback or a bargain that will more than do the job.
If you gonna buy new, you can't really go wrong kite choice, But build quiality I would say slingshot airush and North.
Second hand just make sure you look for tell tale signs of a hard life. Compare to other kites you have seen, talk to loads of people about best thing for learners and MAKE you OWN mind up.
Fly the kite you are buying too, make sure you feel comfortable with it. If second hand make sure it does not drift to one side predominantly.
Good luck, winds up in WA an I am finished work, Yippppeeeeee