20 mil is probably around what we've been quoted! Thats not to say he's worth it!
Like another poster mentioned, I have also heard he wants out of Liverpool, and even put in a transfer request on the eve of their last game of the season, to Swansea, hence why he never featured in the squad!
For what it's worth, I think he'd be a great signing, he would really add proper competition to the CB position, he's a good age, proven in our league, and I think I'm right in saying he has won Liverpools player of the year, 2 years running, Plus he's only missed I think 3 games in the last 2 Premier league seasons.