I can't understand the delusion about the value and saleability of Ng. Don't get me wrong, he's a good player and I'm glad he plays for us. But he's 28 yrs old and an above average Championship right back. Right backs generate the lowest transfer fees of any position. We'd be lucky to get over Ł1 for him and that would be from the likes of Hull or similar.
The only players who have any transfer value greater than that are Colwill and maybe McGuinness. This is a direct result of not developing younger players and signing has beens (this goes back to before Bulut). It results in your squad has no capital/resale value. Recent signings would probably have a negative value (reverse premium).