I didn't know that the majority of funds invested in keeping the place operational for the 13 years was classed as part the purchase price
..?
They bought a business for £10m, spent a further £7m on capex + supported it during their ownership period and then sold it for only £2.3m. That is cash that has been lost forever and hence not benefiting the council tax payers.
Rather than getting lost on what's the definition of purchase price and contextualising this as a good deal, you should focus on the cash that has gone.
I dont believe the councils recieved any money from the sale of HUY shares, as there was a negative net value when Manchester took over.
The councils didn't own HUY, the airport group did. Therefore any cash receipts would have flowed to the airport group from this sale. Again, the point is that this disastrous acquisition resulted in £10m+ less that could be paid out in dividends to the councils of Manchester.
Comparing apples and oranges.
Both HUY and STN are airports and acquisitions that were done by the corporate business that is Manchester airport. It is completely comparing apples & apples. The corporate legal entity which does the acquiring is not relevant.
The policy of undertaking a massive acquisition in another part of the country is not something that a council controlled business should ever be undertaking.