Agree with the 2nd and 3rd paragraphs
The "luxury we can't afford" in your 1st paragraph depends on our ambition and what we can get him to accept to stay.
I see Manga as a John Stones type of player in that he is so much a better footballer than your run of the day mill centre halves. Like Stones, he is prone to making errors because of his style of play, unlike say a no nonsense player like Bamba.
If we were to be in a position for promotion this time next year, after VT and NW have 'performed' then we will need to recruit Bruno Manga type players, i.e. those who can cut it the next level up.
Use all your nous to keep him here Neil and make the figures tally