The club and land i.e. stadium etc... are separate entities. SC owns the club, SB/DG own the land which is held under Brass Bank. As for as I am aware we got told last week. The amount we owe to Blitz is capped at 4m, which will only be repaid if we ever reach the premiership. Effectively, if someone was to buy us, they would have to buy the club, as in OAFC, and then separately negotiate a deal for the stadium/surrounding land.
On the unlikely event the Chinese investors have bought 30%, I am inclined to assume this would be 30% of the club, not the land/stadium.
If a buy-out of the entirety arouse (i.e. everything) I would assume the whole cost would be around 8m, going from figures and land worth.