This machine at ebuyer.com caught my eye:

For your £130 you get AMD Athlon Dual Core K325, 2GB RAM, 250 GB hard drive, NVIDIA GeForce 9200, HDMI out, and Linpus 9.5 Linux. The ER1401 also include wifi, 2 USB ports, S/P DIF digital out, headphone out, wired ethernet, and VGA for a standard computer display.

I probably would not have noticed it, except that I have just purchased a Mac Mini:

The Mac has plenty to offer over the ER1401 of course. There is not only the slick new OS X Lion OS, but also a Thunderbolt port, Bluetooth, 4 USB ports, twice as much hard drive space, memory upgradeable to 8GB rather than 4GB, FireWire 800 port, and an SDXC card slot.

Linux is free, but if you decided to put Windows 7 on your ER1401 the cost would climb a bit.

Still, it happens that the Mac mini, Apple’s cheapest Mac, is just over four times the price of the ER1401. If you just need a small computer to do some task like playing BBC iPlayer on your TV, or running Squeezebox server, the eMachine model wins the value prize.