Fancy manors with greens (for an extortionate sum) (6,5)

'an extortionate sum' is the definition.
(demanding a ransom is a type of extortion)

'fancy manors with greens' is the wordplay.
'fancy' indicates anagramming the letters.
'with' is a charade indicator (letters next to each other).
'greens' becomes 'money' (green or greens can informally mean money).
'manors' anagrammed gives 'ransom'.
'ransom'+'money'='RANSOM MONEY'

'for' acts as a link.