I believe the plan is to
Smithies is a very good keeper and a good fair fee should be the only way forward.
If Cardiff want him for 4mill then don't sell.
On your rationale if Cardiff offered 1 million and are the only team to bid we would sell him as that's what they are willing to pay, therefore his market price.. I think not.
In football it's nothing like the real world, prices, wages etc.players are only worth what someone else is willing to pay. We can value players at whatever you want to but it's meaningless if no-one will pay it. Everyone always thinks that they can do better, always easier on the outside looking in.
Smithies is a very good keeper and a good fair fee should be the only way forward.
If Cardiff want him for 4mill then don't sell.
On your rationale if Cardiff offered 1 million and are the only team to bid we would sell him as that's what they are willing to pay, therefore his market price.. I think not.