Well I have a Sonata and I really like it.
But, based on reviews/comments by others here, I'd say go with the Antec SLK3700AMB for ~$74 (~£50).
But a quick search through Newegg's website, you could do worse than the Enermax FS-501 series cases. Base price starts at $45 (~£30). Granted, that particular case would require about a weekend of intimate closeness with a drill and Dremel tool to cut out the fan grills, and drive grommet mount holes but it's a pretty good case for low cost. If you put two panaflo 80mm L1A's in the back and one 120mm L1A in the front you'd have decent airflow with little noise. Ditch the crap PS and go with your own quiet one.
The fans on the side panel and blowhole invite some wild ducting experimentation!
Alternatively, you could get a plain Evercase 4252 series ~$21 (~£15) but that would require significant work with a dremel tool to be adequate.
It all depends on how much work you're willing to invest. More work=less cost, and vice-versa.
Enermax Pics:
