Jeez, a gen-u-ine C320 Skynight with pax doors, well buggame as the choirboy said to the Anglican priest! That is an OLD aeroplane! There is a more recent example at AF doing survey work I think, but no double doors on that one.
There's one advertised as a fixer-upper project in the AvTrader - 'for a LAME', for only $50K - cost another $180K for 2 x TSIO-540's, $50K for a decent avionics stack, $20K + for P&I, $40K for some props.........
Where can I buy me one of those Nasa-birds...........