I have used these guys a few times and delivery and customer service have been good. Well worth a look as you can get a great bargain now and again.
There are bargain buckets starting from £1.99 per cd although not the greatest selection, there are a few good ones further up the price range.
Although the CD`s are tagged as used, the ones I have purchased hasve been in good as new condition.
www.secondsounds.com