Normally, at least in my area, buying wood by weight is only for small quantities. Once you get up to tons, people normally sell by volume, and I'm pretty sure price is going to vary depending on what state you live in. A standard measure that it's sold by is the cord, which is 4'x4'x8' (1.22m x 1.22m x 2.43m.) If you were to buy a full cord of bucked up, split and cured oak, it might be $400-$500 where I live. That might weigh in around at 3,300lbs (1500kg.) A full cord of pine might be $120-$150. $200 is about what I'd expect somebody to sell a cord of Juniper for. Funny thing is, some people will sell that same cord of Juniper by the wheel barrow load, and they can jack their prices up and they might make $300-$500 from a lot of small sales. You do get a bulk discount. Except for oak, I've never seen woods suitable for smoking sold by the cord where I live, so I cannot comment on things like hickory, apple, cherry, etc... Around here, you normally get a lot of that stuff by pruning or removing somebody's tree when it needs it. They sell it in small quantities at Lowes and Home Depot. Though I don't normally buy that stuff, but Home Depot has hickory listed at ~$7 for a 5lb bag.
FYI, the exchange rate right now is ~1.0486 USD to 1.00 AUD.