$30 is limiting - especially in the UK where things tend to cost a lot. Most people on head-fi would suggest the KSC75 (which are probably within that price range, but maybe not in the UK? even available?), the PX100 if you can stretch it a bit or the Alessandro MS1 - which is $99 American shipped free to anywhere in the world. This is really similar to the Grado SR80 which I have, but it would cost probably $150 or more in the UK. If you're really interested in getting the best bang for your buck, I suggest browsing head-fi.