From what I've seen and read, Hamer seems happy here and happy with his situation.
He's clearly never going to be the epitome of fitness but even if he's a bit overweight and not as fit as he could/should be, he's still far and away our best and most talented player while earning very good money. He could move to another club for an extra £10-20k a week but then he will most likely be forced in to changing his entire lifestyle only to end up back in the championship eating lettuce and no alcohol. Here he can do everything he wants, live the life he wants, eat and drink everything he wants, and still be adored by the majority. Ambition is overrated!
We're not going to replace Hamer for £5m we might get for him, just like we'll never replace Ndiaye or Berge for £15m apiece, we've never got close to replacing Norwood for the £2m we spent on him, and so on. If Hamer goes this summer we are heading for a few years of mid table oblivion.