As far as i'm aware he would cost no more than 2 mil in compo.
With Vidic coming back from a long term injury, Rio with permanent injury problems (not to mention getting on a bit) and Fabio (as well as possibly Fryers) going out on loan Clyne gives real competition for right back with better attacking play than Jones.
Clyne's contract is up, he is cheap, in one or two years Rio will leave and Jones and Smalling will be two of only four centre backs and will not be providing right back cover, luckily we will have had Clyne at the club for one/two seasons letting him settle in and improve both himself, through being here, as well as Rafael, though giving him competition at right back.
Our right back and centre back positions will be adequately covered with settled in players all in their natural positions