Your money's worth giving for tea clue? (4,2,8)
I believe the answer is:
rate of exchange
'your money's worth' is the definition.
'giving for tea clue?' is the wordplay.
'giving' indicates an anagram (the letters give the letters for another word).
'clue?' becomes 'exchange' (I am not sure about this - if you are sure you should believe this answer much more).
'for'+'tea'='fortea'
'fortea' anagrammed gives 'rateof'.
'rateof'+'exchange'='RATE OF EXCHANGE'
Can you help me to learn more?
(Other definitions for rate of exchange that I've seen before include "Get it for a few pounds" , "speed one bargains?" .)