Latest update on Manston courtesy of the local newspaper. RSP already spent £15M on pursuing the Development Consent Order (DCO) and the purchase of the Jentex Fuel site.
The figure quoted from DCO documents is that £16,5M has been agreed for the purchase of the airport site.
I can't quote a source, but, it is believed that RSP expect to expend £100M on developing the airport. At the time I attended a presentation by RSP, they stated their intention to have 10 aprons capable of taking 747 sized aircraft, before re-opening.