£6 a set for the epson r200/220 arndale media manchester... they do the northern computer fair at bowlers trafford park every saturday. I use nothing but compatibles, and so do all my family and friends, non of us have had any probs with them... I've used them for about 8 years. and if they do mess up, it would still work out cheaper in the long run to go out and buy a new printer.
http://www.computermarkets.co.uk/