As of a 6/5/12 recheck, the price has jumped up up up and away!
The price of the used Fuji X10 at Amazon Warehouse Deals has dropped to $373~ with free shipping. This is for the "Used (very good)" condition listing offered by Amazon Warehouse Deals. Prices can change at any time and for any reason!
It comes with a 30-day return policy but no warranty. You can optionally purchase an aftermarket warranty for $extra$. This as we just updated the X10 stock status page.
Please note used camera gear has its own risks and rewards. Don't be tempted by the price unless you understand the risk and reward trade-offs of buying used! Also, since it doesn't come with a warranty, it may be a good idea to spend some time with the camera after you receive it to thoroughly test it out before the 30-day return window closes.
For a refresher on the camera, check its list of reviews. Please note that there is also an on-going ORB issue with the camera. Just look at any Fuji forum or google it and you will find more details than you can ever find time to read.