For sale through yahoo Japan
http://page8.auctions.yahoo.co.jp/jp/auction/h133280255

That's a pretty decent set, I like the white pegs. This seller won't ship internationally, though, so here's the Crescent Shop link. YJA usually has around five good shamisens up for a decent price at any time, but because the price is good they have a tendency to go up at the end of the auction. Here's another one that has everything a person would need and extras, a cheap one that doesn't come with ammenties, another cheapish one with less stuff, a really well priced set that's bound to go up in price, another really cheap one, another cheap one, this one has built in note marks (super cool), another one with a good price. I expect most of the ones under 10,000 yen will go over it around the end of their auction. There are also more options open to people willing to buy a shamisen with a torn skin, because I know of a guy in Maryland who can reskin a shamisen with either dog or cat skin (I had him reskin my shamisen in dog skin for $120).

Also, something to keep in mind when buying a shamisen is the size of it. Not all shamisen are built the same, there are three sizes of shamisen that effect the sound. The smallest one, the hosozao, is used in nagauta and kouta, the chuzao is used for jiuta (sometimes played in kabuki and by geisha), and the futozao is used for Tsugaru (folk music and like the Yoshida Brothers, and joruri, which is used in Bungaku theater). Most of us will probably want the hosozao or chuzao.

Hi, Fuyouhime!
I agree with your data on auction shamisens. I would like to add a bit more. One of the expensive shamisens you linked to had some good pix. The white tuning pegs are probably ivory, one sign of a good instrument. Presumably this could cause problems on an international shipment. In one of the photos, on the upper bridge, you could see a small '18k' mark. Yes, gold is used for this on good shamisens, also on the sockets that the tuning pegs go into. Also, the holes in the neck where the pieces fit together are lined with a similar material (probably not 18k, too soft, but it often looks gold or coppery). These liners provide stability to keep the neck firm and straight. A practice-level instrument will use a cheaper metal for fittings, you can tell because they are usually tarnished. And cheaper shamisens don't have linings in the sockets that hold the neck together.

One of the linked shamis had skin that was almost transparent--you could see the inner edge of the wood body. This is a plastic substitute for leather. It seems it last forever. The drawback is the sound is not good, and it can cause a fair amount of jolting energy to go back into your wrist, if you play a lot.

Good luck in your hunt for a good instrument! Also, try to find out if there is someone in your area who can repair the leather.
Regards, T