Popular Ebay Retailer, The Phone Outlet, is selling the HTC One X (otherwise known as the S720e) for as little as £349.98.
The smartphone is a refurbished one and is SIM Free/unlocked. The items come with only 90 days warranty, are customer returns and come with the battery and charger as a minimum with user guides, USB/data cables, carry cases and other accessories being optional.
The HTC One X is the only other mainstream, widely available quad core rival to the S3. Like the latter, it comes with an 8-megapixel camera (with full HD recording, a F2.0 aperture, BSI sensor and 28mm lens) , a 1,280 x 720 pixels capacitive display (a 4.7in Super IPS model in HTC's case), a quad core Nvidia Tegra 3 processor clocked at 1.5GHz and 1GB of RAM.
The One X however offers 32GB onboard storage (though without any microSD card slot) plus a front facing 1.3-megapixel webcam, a 1800mAh battery, GPS, Bluetooth 4.0, Wi-Fi, Beats Audio technology, HTC Watch, NFC & DLNA functionality plus a microUSB port.
This is by far the cheapest refurbished quad core smartphone we've seen until now and at the time of writing there seemed to be plenty of stock remaining.
Source : Ebay