The HP Proliant G7 N54L microserver can be had from a mere £188 after a £100 cashback from the manufacturer; the original cost of the N54L (otherwise known as the 704941-421) is £188 including delivery at Ebuyer. While the server is not very different from previous generation of microservers, the current pricing is significantly higher given that its predecessor could be had for around £100 after cashback.
The N54L is a very capable device which can easily transform into a web server or a dedicated NAS (thanks to the likes of FreeNAS). It has four internal bays (which means that you can fit in up to 16TB of storage) plus you can always use an adaptor to fit another one in the front accessible bay.
Other features include an AMD Turion II Neo dual-core processor clocked at 2.2GHz with 2MB L2 cache, an integrated AMD video controller, RAID1/0, PCI Express x1 and PCI x16 slots, GbE port (controlled by an HP NC107i), VGA, eSATA, six USB ports and a 150W PSU.
There's also 2GB of RAM and a 250GB hard disk drive spinning at 7,200RPM. You should be able to upgrade the server to 16GB using two 8GB memory module. Make sure you use high quality ones though.