September15, 2008:  While second hand weapons sell at a large discount (often over 70 percent), after half a century or so, working examples of surviving weapons sell at a large premium. A recent auction saw a 1945 British Spitfire fighter selling for $1.8 million. That's about three times what the aircraft sold for new (adjusted for inflation.) Earlier model Spitfires sell for over $3 million.

Many other antique (over 25 years old) weapons sell for more than they originally cost. Aircraft have the highest multiple. Infantry weapons, especially rifles, often sell for little more than they originally cost. That's adjusted for inflation, with twelve the current multiple for original World War II era prices.

For example, a high grade American M1 Garand rifle sells for up to $1500, about twice the original cost (again, adjusted for inflation). Like several other popular infantry weapons (the British Enfield, the German Mauser 98), the Garand was made in large quantities (5.5 million), and many are still in use, and not in the condition collectors are willing to pay big bucks for. These worn out antiques can be bought (assuming the owner does not use it to kill and rob you) very cheap (a hundred dollars or less).

Antique tanks are not as popular as aircraft, partly because they are heavier, and more difficult to move around. There may also be legal problems with the weapons, and using it on public roads. That's because the tracks tend to tear up roads. That said, it's easier to restore a tank to running condition. Sturdier components and all that. World War II tanks in running condition can still cost about as much as World War II fighter aircraft, and non-running models much less. Post World War II tanks are also available, with some countries selling them off to collectors, with the weapons modified so they can no longer fire. There are also collectors of older support vehicles, with restored World War II military trucks growing in popularity.

Antique warships are out there, but usually belonging to governments or non-profit groups (as tourist attractions). These ships are very expensive to restore and maintain, so there are few private collectors of entire ships (and only small ones at that.) Lots of collectors of ship gear, and military equipment in general.

Collectors of artillery, or stuff like land mines, are also out there, despite possible legal issues. But some types of weapons sustain a  lasting appeal to public, and private, collectors. Thus few items are as impressive as an antique warplane restored to flying condition. When these are in the air, a lot more people can see them, and that is part of their allure. And the reason why these collectibles cost so much more than they originally did.