Feather straights

I noticed that these go for a lot of money on the bay. There's currently one offered for 1775$ by a japanese seller.What's so special about these straights? Are they that good?

Edit: I just wanted to make clear that I don't mean the ones with disposable blades but real straights.

I think it's just that seller. I have seen some in the past on Yahoo Japan Auction that they didn't even go for half of that.

That seller has a reputation for selling straights at high prices. But 50% of 1700$ is still a lot of money.