I would assume that the term "big cheese" is ironic; I am sure "big " would be used at RLHQ.
We must ask, why would he buy it? He has suggested an interest in the past but not recently. If he left Salford (and he has never alluded to being here permanently), it would be a millstone around his neck. He is a businessman and so would choose whether the outlay (financial and personal) would be worth the returns.
Sale is different: they could turn the albatross into a success by utilising it as a regional flagship for Rugby Union: you can see financial support and kudos coming from the wealthy RU game.
This can be shown easliy: Sky have paid something in the area of £30 million to cover the non-6 nation England Internationals until 2020.(
Imagine what they would have got to include the 6 Nations ... not that the Beeb and ITV would give such up.) Twickenham will be the venue for the games but there is always the possibility of Youth and Women's matches played elsewhere. Somewhere easily used by Cheshire, the Manchester area and Liverpool.
It's more in their interest to own such a stadium than the good Doctor's. I doubt the 'wealthy' RL would help him as much as RU would help Sale. Especially as the French RU have now attracted TV rights of over £300 million (for the top 14 clubs over 4 years) which will mean the English clubs will lose players to the wealthy French.