Basic Australia Post costs:
$9.50 for 500 grams tracked 4-5 standard comics plus cardboard support.
Australia Post Satchels range from Small $12.50, Medium $16.50, Large $20.50, Very Large $24.50.
Magazine sized comics weigh more than standard comics, so you will get less for the costs.
Message me and tell me which comics you wish to buy, I can then give you an accurate postage cost based on number and weight before payment.