A popular server retailer from eBay, Bargain Hardware, is selling the Viglen HX120a, a 1U rack-mounted server for a mere £100, a price that includes delivery, a free rack rail kit and 100 Nectar points.
The server can run VMWare ESX and ESXi up to version 3.5 but not beyond. It is also compatible with Microsoft Windows Server 2008 R2 but not with its Hyper-V feature. Not bad for something that costs less than some entry level Android smartphones on the market.
The HX120a is powered by two AMD Opteron processors, the 270 series, each clocked at 2GHz. There's also 16GB of DDR ECC RAM (which means that the server is almost 10 years old), a hard disk drive controller with dual ATA 133/100 EIDE channels support up to four UDMA IDE devices (which limits its hard disk capacity), three 3.5in empty hard disk bays, an ATI Rage XL 8MB PCI Graphics controller, a Broadcom 5704 Dual Port Gigabit Ethernet Controller, a 420W non-redundant, non-swappable power supply, a PCI-X expansion slot, five USB 1.1 ports, a pair of serial and PS2 mouse ports.
It is worth noting that this server doesn't come with an optical drive and that it doesn't carry any form of warranty other than DoA.