Leyla, I recalled that Greenpatch Seeds in NSW had it in their catalogue but on checking their website could not find it in their lists. I emailed them to see if they still stocked it. Here is their reply:

"We have been harvesting seed and getting another stock of the Indian Curry Tree (Murraya koenigii) ready for our next catalogue. They are not ready for posting yet and will require another 2 months or so. They will be priced at $7.00 each plus postage."

This may help if you aren't able to locate it elsewhere.

Thank you for your trouble Anna, I will contact them asap and ask them to put one on order for me
Regards Leyla

I've seen them at nurseries more and more in recent years. Bunnnings garden centre had them, about 5ft tall and well established. Growing from seed would be very slow, you should shop around your local nurseries or ask them to order you one.