Wilson is out for more or less the whole season. Done his cruciate ligament in back in September so will be out for 6 months and will need time to get match fit.
The one glaring thing that you're overlooking is that Calleri would have a sale on value that would be at least be equal (probably more) than that which would be paid to Boca. With Murray you would have to look on it as an out going expense that won't ever be recovered.