Assess support for dialogue on the relative value of money (8,4)
I believe the answer is:
exchange rate
'money' is the definition.
The answer and definition can be both related to property as well as being singular nouns.
Maybe there's a link between them I don't understand?
'assess support for dialogue on the relative value' is the wordplay.
'assess' becomes 'rate' (rating is a kind of assessing).
'support for' is a charade indicator (letters next to each other) (in a down clue, some letters \'support\' others).
'dialogue on the relative value' becomes 'exchange' (I can't justify this - if you can you should give a lot more credence to this answer).
'rate' put after 'exchange' is 'EXCHANGE RATE'.
'of' acts as a link.
Can you help me to learn more?
(Other definitions for exchange rate that I've seen before include "various notes in a relationship?" , "Figure used when converting currency" , "Price of one currency in another" .)