Hey Hudo,
Sorry you ended up with a bit of a lemon. The 2nd hand market is full to the brim with crap. As a newbie entering the sport it is extremely enticing to see all the gear available in the classified section and indeed there are some absolute bargains,
if you know what you're looking at, otherwise it is like a stab in the dark.
It sounds like you have been sold a dud by an unscrupulous seller, the old gaastra kites weren't much chop even when new, but that also depends on the year and model you bought.
A pump can be purchased from Ranger camping or any good camping store for a little more than half the cost of the same item in a kiteshop. A 14m kite in Perth is a damn big kite, especially if it is an older "C" kite, considering the winds we are experiencing at the moment. Unless you are in the vicinity of 100kg it is just too big for anything other than light winds.
We, or most reputable kite shops in your local, can sell you a quality new leash for around $30. It is quite likely that the lines are still original and if super short are indications that the kite has been used for training purposes. I'd replace the lines if I were you. A new line set will set you back around $200 for a set of 4. And to be honest, If you are going to keep the kite, I'd seriously look at 5th lining it so the line set will be a bit extra or you can ask around on the forums here as I'm sure someone will have an old single line kickin' around their garage or shed they'd be happy to part with for a 6 pack.
A new modern Airush "trigger release" Chicken loop with spectra centre line is around $90. This should go a long way to turning the lemon into a peach.
You can have a look on our website to gain a greater understanding of what items I am talking about. Whilst you are there, check out the FAQ page as this is the newbie guide to all things kiting, it will help you know what you are reading about.
Better still, bring your purchase with you and come and see us at the beach and we'll help you sort out your kite and give you as much free advice as you can handle.
Sorry you got duped, that sux, but as you said, "let the buyer beware". Hope you and any others considering buying 2nd hand without experienced advice learned something.
Good winds and Happy New Years,