I suspect it has a bit to do with the release of the dragons... Year of the Tiger coin prices sky-rocketing. eg. 1oz 2010 silver tiger currently bid up to US$96, with 2hrs remaining. http://www.ebay.com.au/itm/2010-AUSTRALIAN-LUNAR-YEAR-TIGER-1-oz-SILVER-COIN-BU-/180713244027
I wouldn't use that sale as a guide for prices. Very odd bidding with a very experienced buyer bidding up that coin and another one just like it. Somebody wants some tigers bad. Man I wish I could contact that person. For those kind of prices, I might let a few tigers out of their cages. lol
Actually.... premiums are jumping everywhere! If you prefer, Apmex have 23 of them for $100 each. http://www.apmex.com/Product/54872/2010_1_oz_Silver_Australian_Year_of_the_Tiger_Coin.aspx
I've been watching a lot of auctions for S1, all the premiums are jumping, just some more than others. Dragon, Horse, Snake and Tiger have moved up a lot. Rabbit, Ox and Monkey getting up there too. Pig, Rooster and Dog still relatively "affordable".
Apmex is higher on everything, so I normally don't use them as a price guide. And when I looked the other day, the tigers were still cheaper than the rabbits. However, as you mentioned, they are down to 23 tigers and raised the price about $40. Ebay is usually a little higher than true market, but this one bidder is skewing things. I hope the price stays up near $100. Me and my 500 tigers would be purring like kittens. If the price really stays up there and normal sellers can actually sell for that price, 100 of my tigers will be freed from their cages and the money will go into buying 200 ounces of ASEs or some other more reasonably priced silver.
Looking at the completed listings of actual sales, 1oz tigers seem to be selling in the $75-$90 range.