Dann has improved a lot since he moved to the PL, but he will always be quite a slow player. On one hand Birmingham fell apart and got relegated in no small part because he got injured, and on the other he was (with Johnson) in an ultra defensive Alex McLeish side, which always helps defenders. Even Stephen Carr, who was virtually retired, looked really good in that back four.
The other factor is how well he has returned from his injury. As he's now playing for a Championship side I wouldn't pay more than £10m for him, but I can see Birmingham getting £15m. Loaning or giving them players is always easy for a Championship side too.
Where is Danny Wilson anyway?