It could have nothing to do with money. It could something completely obscure, if the case was they were far apart we probably would have heard something by now about it. It could be like Tatar where they were just different on how long they wanted the contract to be for.
I wonder if they're trying to gauge whether Alfredson will be playing or not, and basing how much money is potentially available, and how to structure the contract on that. It would explain the delay in signing a contract, and it would also explain why both Holland and Dekeyser seem like they aren't too worried about Dekeyser not signing here.