Being from the USA, I just relied upon my search engine to find the answer about broth. While I found a website selling dehydrated broths of all kinds, the prices seem very high to me http://www.brothoflife.com.au/ .

The thing about bone broth is not just the salt, because that's so cheap and easy to sprinkle on. It's the gelatin that is extracted from the bones which give more nutrition.

So it depends upon what you want from your broth. Here's another online resource:
http://thestockmerchant.com.au/buy/

Good luck.