I think Moyes purposefully lets his contract run down to give him some leverage with the board when negotiating transfer budgets. If he went to Spurs we would get a pittance in compensation as he only has a year left, so Bill needs to keep him sweet and try to get him to sign a new deal. Where he finds money from is another issue.
Maybe Davey wants to stick around and see our fine crop of youth come through? We probably have the best group of youngsters in the clubs history. Having nurtured them for so long I think he'd find it hard to walk away before they realise their potential.
He tried that with Hibbert, look where that got him.........................
I think I recall him waiting a while last time at Contract renewal time, I guess thats how he rolls, maybe it is as you say, a bargaining tool.