My optimistic answer would be that Stockton is our second choice and that we are in talks with another striker, one that we're willing to pay a decent fee for. In this scenario we're holding off making a bid for Stockton because we are hopeful of signing our number one target. If it doesn't come off, we move in for Stockton.
We cannot avoid paying a fee for Stockton as he's contracted until 2023 so it can't be that. The only other thing I can think of is we're hoping Stockton flat out rejects Morecambes contract offer, puts in a transfer request and effectively puts pressure on them to do business. While ever Stockton is still in talks with Morecambe they will keep the price as high as they can as there's a glimmer of hope he might stay. But if he does a Ladapo then they might have to listen to more reasonable offers?