Royal couple married for money in Oslo (5)
I believe the answer is:
krone
'money in oslo' is the definition.
'krone' can be an answer for 'money' (I've seen this before). I am not certain of the 'in oslo' bit.
'royal couple married' is the wordplay.
'royal couple' means two replacements for 'royal'.
'royal' becomes 'k' (abbreviation for king).
'royal' becomes 'r' (abbreviation).
'married' becomes 'one' (I've seen this in another clue).
'k'+'r'+'one'='KRONE'
'for' is the link.
Can you help me to learn more?
(Other definitions for krone that I've seen before include "Danish bread" , "Danish or Norwegian currency unit" , "Norwegian capital" , "foreign currency" , "European currency" .)