There is a great deal of competition in the UK for contracting roles. You need to price your self so you will get a contract but not undervalue yourself. That's why I suggested that looking at CWJobs is a good idea. Work out what the competition are charging and vary your rate depending on what you can bring to the table. Contractors tend to be paid more than perm staff (in the UK) so I assume that the OP is looking for more money and has fair idea of what they can live on.
Steve0 You can't polish a turd.