That's right, this auction for a third-series Rockman X3 "Factory Figure D" set, said to be a rare item by the seller, is available for the next day and a half for a starting bid of $700 (plus $15 for shipping if you win).
It is an interesting find, brought to our attention by the seller, Oyajitchi. However, according Heat Man, this is something of a "caveat emptor" situation. He notes that, as you might expect, it is a pretty old toy, and is one of four sets available (this being the "D" figure). They usually had candy with them, or even inside them, along with an uncolored figure, all for ¥300 when they were released. They are difficult to come by today, but are cheap little toys as well; it's up to you to decide whether the price jump is worth it for your collection.
That said, Oyajitchi notes that if this auction does well, then he'll post more figures from the series. Whether you're interested in buying or just want to see if anyone else is, you can find the auction here.