Ive got a front end and tank etc to post out. Just wondering what the best way, aus post, couriers etc? any help would be great

hey mate its just within Australia I actually just worked out interparcel before didnt know it existed. Just fucked up and send off some forward controls via post.. Cost 37 bucks. When i could have put them into 2x3kgs postage bags.. As soon as i left the post office i worked out what a dumb ass i am