Are All hyundai lantra keys the same or do they have chips in them? I have a 1998 hyundai lantra. I have lost my key. It didn't have any buttons or anything to press. It was just a plain key. I'm after a new key as I lost my only one. I live in Brisbane Australia. Every person I have called have quoted me 3-400 $ average for a replacement which is a lot if I am only going to pay for s key. Any help would be much appreciated.

They aren't all the same, I can say that much. It's rare but with some of the older 90's cars dependent on your exact lock and what kind of key you get its possible they can work.
Eg. early 90's Camry's came with such a basic key they could usually open other Camrys and even other Japanese cars.
I know you've said that you've already tried places but I think you'll find that you'll be better off sourcing a new key.
Try Car wreckers in your area?
or a more in depth search online perhaps?