In my post on Sunday, I used the figure of $500 million for the cost of the Australian gun buyback, but you might argue that it was a bit cheaper than that, as the Gun Control Australia website explains:
There were about four million guns in Australia. One million were no longer in the legal category so a gun buy-back scheme was introduced to purchase these. The estimated average price was $500 per gun. Hence 500 million dollars was set aside. Only 640,000 guns were offered for purchase, hence $320 million was used or this purpose. About another 40 million dollars was used for administration and assistance to gun traders. Since the 500 million dollars had come from a medical levy the balance was distributed to medical research and welfare.