I've packed and sent plenty of pins without incident. My tip would be to go to a bike store, or an appliance store and ask them for their leftover cardboard. Bike stores in particular have THICKER cardboard. Also, it's free and better than buying recycled cardboard.
After wrapping the game in cardboard, use plastic wrap and then finish it off with GOOD QUALITY packing tape. Don't buy the cheap bunnings tape that is sold in rolls cheap.
I packed a machine for Gavin (retropin's Rally Comics) and I used a discarded Plasma TV packing box. Took me two hours to wrap properly - but it took him half a day to unpack 
...And filled up the recycle bin!
