This price got me shocked big time. It's a regular Japanese 1981 10 yen coin (worth around 10 US cents) but unless you are a serious collector, a lot would have missed this. In fact, this variety was not in Japanese catalog for a while until very recently. http://page9.auctions.yahoo.co.jp/jp/auction/k162281872 Asking price is around 1800 USD http://page6.auctions.yahoo.co.jp/jp/auction/f126699850 Currently going at around 400 USD So what makes this coin rare? Appearently it was decided that a modified design of the temple would be used in 1982. For some reason, it was discovered recently that some coins were accidently muled during late 1981, making them rather scarce. Mintage for this year is 1,369,000,000 followed by a drop in 1982 at 890,000,000. Note that previous years mintage averaged more than 1.2 billion since 1973. (Yes I double checked the figures with Japan mint - http://www.mint.go.jp/eng/coin-eng/eng_number_of_coin_production.html ) My 2011 JNDA catalog does not give a breakdown of what the price difference is but you can tell one's worth signifcantly higher than the other. Japanese error coins are not common but they do appear once in a blue moon, available at moon currency. Will try and get around to post the differences - appearently it's quite minimal but obvious.
I've tried to edit the post as I've got the year wrong - it's actually 1986 instead of 1981. Bit of a brain fart. But the mule still is valid.
