Just buy large letter bubble envelopes and post via $2 large letter (if under 125g)
There is no tracking, but I find it's much cheaper to do it that way

The bubble envolpes are size 1 or 160x230mm and I think I paid around $30 for 200. Case offers enough protection and the envelopes are strong

An example is below

http://www.ebay.com.au/itm/200-01-Bubble-Envelope-160x230mm-Padded-Bag-Mailer-SIZE-01-White-Printed-...