I just don't get this argument tbh.
If money is all 'the hierarchy' are interested in why flog him to death. Why not sell him now and make a big profit, job done and sensible if you think his form might fade.
Rigg's value hasn't changed despite him not playing ...
.. and, by default, the value of our entire squad would increase in the PL.
Irrespective of that, the cash income, for promotion would make any increase in Jobe's value totally irrelevant.
I'd say that playing regularly in a top half Championship, as an 18 year old, is quite successful ...
... and Speakman has transformed the squad, as a whole, it's not dependent on just one player imo.