Nikon D3000 can be had for around £300 with a 18-55 mm lens, or a Canon EOS 1000D for about the same price with a 18-55mm lens. I'm a Nikon owner but I have to say if I was going to go low end, I like the images that come of the Canon more.
I started of with a D40 and kept upgrading, buying lens and other kit along the way, once you pick a brand you kind of have to stay with it. Although depending on reviews I'll most likely end up selling my D90 and probably my Panasonic LX3 for a Fujifilm X100 (I don't really need anything other than a 35mm lens).