Yes, it looks as if he got his leg caught somewhere and ended up hanging upside down or sideways thereby not really cutting off the circulation but slowing it down too much. Birds don't really have very good circulation going down to their feet, only one artery going and one vein coming back up so anything that restricts it causes a lot of damage.
Keep him warm (around 28 degrees Celsius - use a heating pad on the bottom of the cage and cover it first with a towel and then with paper) and in a cage half covered with a towel (they feel better if they are not completely exposed when they are sick or wounded) and keep the soft bottom on it. If he is not perching at all, just remove the perches. Ask your vet to prescribe metacam (aka meloxicam), it comes in liquid form and is pretty much the only pain killer and anti-inflammatory we use on birds. If he doesn't have any, ask him for a prescription and see if you can get it filled up in a regular pharmacy (I don't know what the system is in Oz but here, human pharmacies also fill veterinary prescriptions). If neither works, see if you can find a local wildlife rehabber, they always have medicines for birds. The dosage for a budgie is 0.01 ml (the very first line on the tiny syringe) twice a day (insert the tip of the syringe on the left side of the bird's beak and pointing it downward -so it doesn't shoot the medicine to the throat and the bird ends up aspirating it into its lungs- toward the center of the bottom beak, press the plunger). It will help with the pain. If you see red and swelling developing, ask your vet to give you some liquid enrofloxacin (Baytril) for him but it doesn't look like it's infected to me.
Aside from that, all you can do is just wait and see what happens. It could be that it's just real bad bruising and, as it gets absorbed back, movement will be restored but, even if he cannot use the leg at all, he can still have a good life.





