I wonder, how do you tell the difference between this (Taken on a £30 Camera) and something costing over £1000?
-snip-
Well, this issue is debatable. If you give a pro photographer a £30 camera, it's almost guaranteed that the final image taken (of anything) will be better than an image taken by a ... shall we say a n00b with a Canon 1DS Mark III.
That's due to the experience the pro has, and the composition, and the techniques he knows blah blah blah blah...
On the technical side, however, there are many differences, albeit maybe a little difficult to discern. There is a
lot more 'flexibility' with a reflex camera. Even though you can buy cameras to the likes of the Canon Powershot G12, which has quite a few similar features to entry level DSLRs, that would be a different price bracket to a £30 camera.
If we do take a £30 camera, you'll find that pretty much the only functionality it has is changing modes (you'll be lucky if it comes with more than 2

), and taking pictures. Nope, sadly no transformers option here.
So, with a camera as discussed, a pro/amateur will only have the most basic functionalities, limiting his/her creativity, therefore making a picture look dull and 'normal.' Furthermore, for the camera to actually be profitable to the company who makes it, the parts will have to be relatively cheap, correlating with them being relatively low quality and cheaply made. This means that the sensor used will be most likely 'old', and , well, bad. The camera will most likely automatically choose the ISO, shutter speed, and aperture for you, and, as all things electronic goes, it might not be fully accurate (especially since the metering system will be useless, and the AF system will be 🤬).
Now, with a DSLR (especially £1000 ones - body only - ), come with state of the art technology. Someone who really knows their equipment will be able to fully take advantage of all said camera, and compose some brilliant pictures. The quality will be extremely crisp (OK, lots of variables here, but whatever), and you'll be able to crop the photo to an amazingly detailed shot and still retain most of the quality (this is more due to MP size though). With one of these you'll be able to achieve professional shots you see in advertising everywhere, something you won't be able to get with a cheap point-and shoot.
So, basically, with a cheapo camera, you'll get basic shots, ok quality (although you can get superb composition), and with a pro camera, you'll have a LOT more flexibility, which has its advantages

.
-- Sorry for the long post, just trying to help (: . Oh, I'm not an expert on this by any means, so process the information at your own risk.