Where can I find a cheap SLR Camera?

I need a new camera next year for college. A SLR to be precise, but the one I would like is quite expensive(£500).It's a Nikon D3100, and so I want to be able to get it before September next year. If you know of any good, suitable places online that will NOT scam me, then please could you direct me to the site?

If you what to buy used check out KEH Used Cameras.

You can try e-bay or try your luck at any of any of these stores who all do second hand cameras:
:
London Camera Exchange
Cash Converters
Computer Exchange (CEX)

Have a look on Ebay, Also Try Websites for various major stores and then compare prices, and go for the best deal you can find.

I wouldn't get the D3100 if I were you. It's a consumer camera, not a student camera.

I'd say have a look at used D80's or Canon 30D's on ebay and gumtree. They are cheaper than your D3100 and better too. You get all the ergonomics you would find on a professional Canon or Nikon, as well as a better build quality than any entry level SLR.

The D80 or 30D will also be cheaper and come with a better lens (either the AF-S DX Nikkor 18-105mm VR or the Canon EF-S 17-85mm IS), and you'll have enough money left over to get a 50mm f1.8 lens (of either manufacturer) and probably a Metz 48AF1 flashgun.

I'll put this simply, a D3100 and 18-55mm lens is not good enough for a college course.