http://www.gioadsl.co.uk/
there offering 150 at £15.95
256@ £17.95
500£19. 95
1000@£2 9.95
2000@£3 9.95
there is a activation fee of £59.99
but they also do the 500 with free modem and activation not sure on that price
they do cheap isdn and normal 56k aswell the anytime in various options