A better way may be to pass around a box of surplus and not-my-cup-of-tea-but-may-be-someone-else's items of up to 3kg, using a flat-rate prepaid mailing bag – costing A$13.80 to ship between any two points in Australia –
I wouldn't say the 3kg satchels are enormous, certainly not in physical dimensions or volume. I have a stack of flat-packed, generic mailing boxes that are designed to just fit inside 3kg satchels, and the boxes aren't that large at all at 270x200x95mm. They won't fit inside the new 1kg satchels.
It weighed 2.77kg so under the 3kg mark, kept it a bit cheaper.
Australia Post's Parcel Post structure is about to change, effective 30 September 2019
It might be time to move the contents into a slightly smaller box (to fit inside a 390×270mm satchel). That will bring down the postage charges while the weight limit goes up to 5kg.
Let's give each other due respect, and approach discussion rigorously. I believe we're all peers and equals here as fellow hobbyists, with common interests in the acquisition and use of fountain pens, but no shared values and no obligation to offer each other moral support for one's narrative.
Don't think 'cos I understand, I care
Don't think 'cos I'm talking, we're friends
— '6 Underground' by Sneaker Pimps